Hello!
I'am Jacob, im master when im play Garen.
Im 1250+elo, but i think that guide help u.

Im want to show u build,masteries,runes and a strategy in the game.

PS: Sorry for my english friends! Iam not best on that, but im want to more players can understand my guide.
PS2: It my first tutorial, so i dont know how to use BB codes already, im need to learn that, but not now.

If Garen has not taken damage from any source except minions in the last 9 seconds, he will regenerate 0.5% of his maximum health per second.

Good passive, giving u very huge health regeneration with FoN. Helps u keep sustain in laning phase, but can be easily broken by harras.
Decisive Strike

Garen breaks free from all slows affecting him and gains 35% movement speed for the duration. Additionally, his next basic attack within 4.5 seconds deals additional physical damage and silences his target.
Decisive Strike can critically strike dealing bonus damage.

It so good skill for harras and counter kassadin,other ap, because silence is strong, but it no a best cc. Works with crit, well makes garen very strong harrasament.
Courage
PASSIVE: Garen's armor and magic resistance are increased by 20%.
ACTIVE: Garen gains a defensive shield for a duration, reducing incoming damage by 30% and granting 30% crowd control reduction.

It helps winning trade with enemy, because recuction damage and CC. Helps u survive in teamfights also! It nice skill.
Judgment

Garen rapidly spins his sword around his body for 3 seconds, dealing physical damage to nearby enemies every second. Garen ignores unit collision while spinning, but moves 20% slower when traveling directly through minions.
Garen can deactivate Judgment early by activating the ability again after 0.5 seconds. Judgment can critically strike dealing bonus damage. Judgment deals 25% less damage to minions and monsters.

My faaavorite skill :)! It named by me spin for win, helps u farming and deal AOE damage in teamfights! Also it giving u very hight boost for burst. Good work with sunfire item, also with yoomuu because crit work in it..
Demacian Justice

Garen calls upon the might of Demacia to attempt to execute an enemy champion, dealing magic damage plus additional damage based on how much health his opponent is missing.

OH MY ... It a tank killer! Deal a damage = every 3health lost = +1dmg. VEERY STRONG ULTIMATE AND MAKES Garen ULTIMATEE KILLER!

Marks, why flat armor pene.?: Because, that increase our damage by Decisive Strike+ Judgment so it nice pick!
Seals, why armor? Because, it help me with trades and in fights.
Gliphs, why magic res. per lvl? Because we dont need ap defence in early, we need it in late game, also it makes Garen much tanky.
Quintessence, why flat armor pene.?: Because, that increase our damage by Decisive Strike+ Judgment so it nice pick!

U can switch:
Quintessence, attack damage also good, but more percent damage is better.
Gliphs, flat magic res is also good, if u like get magic resist faster.
Marks, ad can be good, because increases damage output, but im thing better reduce -%dmg dealed from skills,attack.

9/21/0
Why? Because it giving me more tanky, and reductions CC, health help me survive!
Im taking an ignite uprgdate, because 5bonus damage in early is hight.
It giving also armor pene,more attack damage & speed.
If u want play more agressive, pick 21/9/0.
Pick a 6% bonus damage when enemie health is less than 40%, it good work with your Demacian Justice.
To build that, go with that build: Brute force 3>Alacrity 4>Deadliness 2>Weapon Execite 1>Havoc 3>Lifesteal 3>Armor pene 3>Final masterie in offensive 1

In build u get an nice boost for health, health regen, and more tanky topics.
U also see yomuu, for boost your Judgment and Decisive Strike by crit and AD, also mov speed for run.
Omen is one from main items here, its core! It first heart of gold giving gold per 10, also health for sustain. But u can craft Omen, what increases your tanky powers, 30% for slow enemies what attack you, and instant slow & atk speed reduction.

Force of nature increases mov speed & pro health regen + m resist, so it nice pick vs feeded apc.

Warmog, it a core also. Giant health, increases your health + regen when farming minions, u need health..

Sunfire is boost for spin to win, also it boost for health+armor.

Thats why im picking that items!
If u want what other, pick that:

U can switch yoomuu with Frozen Mallet, it also nice pick, speed for chase+crit for Judgment + cd good works.
Also u can change FON for Thornmail, if enemy ad is really really feeded!
Agin thank u for idea MarineCreature!

Okay, this time we say with a items. Force of Nature vs Thornmail
It no horrible question, because just see at enemy team. If enemy got feeded ad carry, and much more character is ad, just take Thornmail.If enemy got feeded ap carry/got much more ap carry, just pick Force of Nature. Frozen Mallet vs Yomuu's Ghostblade, There are harder pick. Im thing Frozen Mallet is good, helping using your combo + health. Yomuu's ghostblade is very good also, because crit makes your Judgment very hight burst, and increases your speed for use your combo. Also dmg+cooldowns help u, because your cd are VEERY hight. Dmg little help's you but no much. Im picking Frozen Mallet

Im first taking Decisive Strike for harras. Alternative u can pick E first, for a better farm. But i like to harras so Decisive Strike would be better in my game style. Next Judgment, for farm a group of minions.
Courage reducing damage & CC so help u win trades, well i pick that in 3lvl.
Max Judgment for farm and more DPS, next Decisive Strike for dmg, next W because better pick first offensive spells for more farm & kills, in late game u tank, no in early.

Flash is very good spell for everything! For save teammates, for kill a minion, for kill a running enemie, for run, and more more more!

For easiner make combo's with E, and help jungler gank. Im picking everytime, because it most usefull (in my opinion) spell in the game. Helps your team catch escaping enemie,

Alternative:
U can pick for catch enemie and ult when low hp, also for run. Im picking when enemy dont got very strong cc, because if u get sloweed after your Q, u losed your ghost for nothing..

U can pick for more damage, and it reducing health regeneration. Very good spell, but i thing more good is Exhaust because it help your team catch enemy.

For clear an farm or trap an enemie, or def tower faster.Also, u can teleport to your top tower, for dont be under-lvl.

Remember, farm is numero uno. U need got an minimum 50farm if enemie zoning u and u cannot farm. If u playing normal, 70+ minimal in 10min. For money u got items, by items u winning.
Use your E to farm everyting everything! E good work with your sunfire.

Your team objective is also dragon, not only kills. Dragon, gives your team 180Global gold. It more than kill.

Early game/laning:
I recommend harras enemy by our Decisive Strike, play passive and farm minions by our E.
If enemy pushing in a early game, call your jungler to gank for first blood.GREAT SUCCES!.
To win trades, u can use your Courage+ Judgment+ Decisive Strike Combo. With that u win everytrade!
One from recomended main work is placing wards. It help u, because enemy jungler cannot
gank u, because u see he/she and u can run into your tower.Best position to place it is in south from your tower bush, because enemy cant attack u from back.
Say ss, it can save your teammates life, so remember.

Mid game/ganking time: It 7-13lvl, when any twoer gets destroyed it starts, or if teammates/enemies start doing that. Now, u can go everywhere u want, and help your allies kill enemies. Also your friends from team, can do that too. Now, u need more use your brain, and create strategy for all moment what can do now.Now, teamfights can be seen in that time, it a 5v5 battle , team vs team, i say more in that topic in final time.

TIP: Garen combo destroying every paper enemy like ad carry (ranged warrior, who build full damage) it deal it so much damage, so focus he/she!

Late game/Teamfights: You ready?! Its time for TEAMFIGHTS! Its time for 5v5 battles, time to say more. U need know to focus ad carry,it deal it so much damage than tank/offtank or something other!In that fight, three topics are kinging here, that:

Tanky: Im recommend to build tanky team, for more chance for survive and win!

AOE DMG: Area of effect damage, well that deal big damage in a area, it help to kill
multiple enemies in short time! So use your spin to win in good position to deal maximum damage.

CC: Crownd control, it a stun/snear/slow/knockback itp. .Your team need it, because it helping everytime.

You got an AOE DMG and Tanky element. Thats why u strong in teamfights, u can inicjate by using Flash+ Courage+ Judgment+ Decisive Strike combo.

ALSO! U need to know def your Ad carry also! If enemy caster want kill she/he, just silence the enemy, AND CHASE EM!

Hmm.. u want more about strategy? Cuz.. okay!
So let me do it!


Start:

In 0:01-2:00 minute u must def blue, to know enemies make inwade or no.

Solo top:

If enemy chasing u everytime (like u) and zoning, call your jungler. If your jungler is in lane, and enemy try escape, use silence, jungler can use their CC for help u with that, and final u must just ult by using Flash+ Demacian Jutice if needed.

If u dont got wards, dont push. If enemy jungler come when u dont wards, and attack u wait for enemy slow or stun, then use your Devisive strike+ Courage combo. Then u lose all of slows and u faster lose other de-buffs. If u die, because your run failed, dont surrender, play and thing: IM CAN WIN THAT! DONT WORRY ''Your name''

Im say that next time, if u dont remember:
Your burst if op, u can win every 1v1 if enemy arent tanky (that's why we counter akali) if enemy is bruiser, it hard to kill enemy fast, it probably be just a trade for u.If its offtank, u can die. Counter for Garen is tanky, and harras. Yorick got that, so u can got very hardd lane.

Great partner for roaming is Lux,

And

Because:
Lux Can snear enemie, then u silencing and make COMBO! Then double ult and enemy die. BYE BYE!


Taric First destroy enemy armor, then stuning enemy, AND U TAKE YOUR OMEGA PRO COMBO.And bye bye cruel world.

Ahh.. And Nunu & Willump Can be good. Because He slows, makes Absolute Zero, u chasing and killing by your Demacian Justice. GREAT SUCCES!

TEAMFIGHTS
U inicjating probably, but if u got an other strong inicjator ( Amumu, Hecarim or whatever like that) U join to party after their inicjate. Then u FLASHING, USING W+E (Use e in central position of enemies, to deal max dmg) AND WIN TEAMFIGHTS!

And... u need also def your ad carry, im saying that 2time to do u remember that. Silence enemes what want do that, then burst em.

Work in programess. Im end this probably today, but chance i will not.

+ Very tanky
+ very good burst without boosting that
+ good sustain (passive)
+ 30% recuded damage by shield
+ good farmer
+ DEMACIA!
+ can counter 3/5 of champions by zoning.
+ no snowballing, hight early dmg.

- No cc, 0,5 silence isnt a best cc evah.
- Hight cooldowns
- No escape mechanism
- No support ablites (like jax stun,anivia wall)
- Passive weak agnist DoT (like teemo poison) and ranged enemies, also agnist harras isnt good.

Hey!
Hey!
Hey!
Yes, you. Thank u for looked to this guide, im sorry for a bad english next time.
Im hope, u winning a games with that build and guide.
I hope, u know how to play that champion after listen.
And next time, thank u!
Bye bye!
See u next time!