Hi, this is my first guide ever! this build is for a quick early dominance to the game, leading to an atmogs to not only beef up your character but to also give it armor and attack. although i later say get banshees veil and force of nature, the last two items are up to u do decide, whether you want armor or more attack at this point is to your choice. i personally go for armor, because i feel that at late game chars do too much damage, and that the extra endurance really matters.

Basically, the goal of this build is to make you a viable threat from start to finish. This guide extends to 5v5s and 3v3s, and i'll try to make a dominion sometime later.

Pros:
-powerful early game
-very flexible gamestyle
-anti stealth, while being balanced

Cons:
-No major CCs (stun, supress, silence)
-not very good for team support

I recommend exhaust and flash, as they are very synergetic with lee. exhaust if useful for running away or chasing, and flash works both ways as well.

Ignite is viable, but not recommended because i dont think its as useful later on. if you do choose to use it, replace cripple mastery with burning embers mastery.

ghost is also viable. its actually very viable, but i just like flash more, because it has a more instantaneous effect. if you cant reach attack range with a flash, u probably shouldnt be ghosting to chase anyways. u cant run away from slows or ccs, but u could with flash.

other spells are just kinda meh. if you really love spells like revive and heal, i wont hate you, but i dont recommend it. its just not worth it.

I prefer 9 Desolation marks, 9 dodge runes, 9 flat cd glyphs, and 3 flat hp quints. the hp quints gives you the early game edge, the dodge just helps you all around, and desolation marks with cd glyphs are essential. However, a cheaper build would just to go all flat AD for pure early game explosive damage.
I must stress especially that the glyphs should be used. this is because lee sin has high end attacking skills, but bad cooldown. later, ill give tips to help you cope with the cooldowns, but the glyphs with the 8% cd is really worth it.

I like to go for a 21-9-0, or a 21-0-9. both are fine, but im a very aggro player, and tend to lean toward the attack masteries. i prefer the defensive masteries simply because they let me stay in lane longer.

This is where things start to matter on whether or not you are on TT or Rift. If you are on TT, try to go solo the top lane. it guarantees first blood for me, every time. The build starts off with a Dorans Blade, then basic boots following up to berserker greaves. If you are ahead of the game, get a Wriggles Lantern. This lets you solo drag while warding it. Even if you arent really leading, get it for the ward and ls. However, if youre team is behind, just settle for a vamp scepter. afterwards, go straight into Warmogs armor, following up with Atma's Impaler for armor, hp, and attack. afterwards, head into a bloodthirster for the damage and extra lifesteal. After this, the rest of the build is up to you. I do recommend that you build armor/mr, but if the other team has no dmg output, you can go for a trinity or IE(very rare). Id build the armor according to the other team. for example, if i see that their carry(s) are ap based, id get Force of Nature or Banshees veil. If they are ad based, good for you, get a frozen heart or thornmail. GA is viable for either situation.

Get q first, no exceptions. it has high damage output, its your only ranged ss, its just too basic to have. after that, you can pick between w and e. if you are facing a ranged champion like tristana or teemo, I'd pick w, so that I can close in very quickly. if youre facing a melee champ like tryndamere or akali, id go with e, because it does damage, and slows move and att spd. after level 2, the rest is very straight forward. just switch off between q and e. It is advisable to get w at lvl 12, but its really up to you.

now, lets put these skills to the test. in early game, if you are soloing in TT, hide in the bushes and wait for the enemy to come. initiate with q, poke twice, then q again. if they persist, poke twice. if they run, exhaust. use ur flash if you must. as far as i know, there is no champ in LoL who can take a double q and 4-6 hits from lee sin.

~When u get w second~
as a lee sin player, i dont mind ranged ppl, but i hate when minions block ur q. smart ranged players will always stay out of your q. this is what the w is for.
lee sin's w lets you dash to any ally. this includes friendly champs, minions, wards, shaco boxes, heimer turrets, and whatever else there are. you can catch ranged players off-guard by teleporting to a minion who wandered off a little close to the enemy. remember that as long as you use an ability, ur two pokes are faster and restore energy. if the ranged char is a hardhitter or has a stun, you also have the option to try to q them, hit, and w away to your minion before they can react. If you use your lantern for dragon in TT, make sure to have it close to the other wall, so that you can blink past walls with the ward. in rift, you can place them at barons, dragons, or wherever else you feel needed. just remember that a lee near a ward is the same as a flash.

~When you get e~
I'm now assuming that you are fighting a melee char like akali, wukong, tryndamere, etc. lee sin's e is very useful, because it activates the moment you press e, kinda like akali's e. in addition, it reveals all units, whether theyre stealthed, or in a bush. i especially like to use this against akali because it renders her veil useless. it also slows the opponent's speed and attack when you press it the second time, so if u need to run, use it. if you want to chase, you can use it if youre in range already, or you can q first then e. other enemies are human after all, theyd rather retreat when theyve been cced or revealed. it gives you more of an impact mentally as well.

~the big R~
what is this exactly? its basically a big kick. it has a small knockback. it does do a good amount of damage. it also knocks up whatever my *projectile* hits. To many of my friends, there are much better ults, and this one is just kinda ****py. I cant disagree, but i do think that this move is highly underrated.when you are escaping, this kick can not only knock back the dude nearest to you, it can stop the entire team. if your q not sufficient to kill that brand behind the alistar? kick alistar, and you get the same results as if you just went up to brand and kicked his balls. of course, getting advanced with this move takes skills as to how you want to aim. You can also use it to ks; kick someone to the side and q them to end it.

Note: when you q someone, the instant after you reach them, you will be behind them. hence, the kick with kick the enemy the other way. useful for dragging out someone for your team to focus.

Your combinations will definately vary, but commonly used ones include:
Q the enemy, double tap, q, double tap for fb
Q, Q, W to harrass
Q, Q, E, poke/E again for harrass/kill
E, double tap, E, q, double tap, q
E, E, attack spammmm, Q, Q (no minions around)
W, double tap E, W, Attack/Q, Attack/Q
Q, Q, E, E (i guess i should get the obvious out of the way)
Q, Q, R(right after 2nd Q) Att/E (to kick enemy into ur team or to drag out a 1v1 fight)
R, Q, Q(put distance before harrassment, another initiator/finisher)

There should be many others, but these are ones i often use. in all the combinations other than the last, R may be placed anywhere in between to finish one off. Also be aware that you can mix combos together for whatever the situation is.

Running Away!
Lee sin has many ways to chase, and therefore should have many ways to run. Here are the main ways:

Just run. o.O
double E them when theyre not in range, but barely out. remember that E is instantaneous, you barely stop to cast it.
go in bush, double E as they get close, w juke.
just W to somewhere
double q to enemy minion or neutral monster
ward @ w (rare one)
the big R
if they are still kinda far from u but are much faster (Yi, rammus) just q into them and r for a juke.

Conc for running: Lee sin is very good at it.

This marks the end to my guide about Lee Sin. Since this is my first time posting a guide, i do not know how to do many things to make it look better and more structured. Helpful comments, critisism, and such are welcome. ill try to update it according to the suggestions every so often.

Thanks for reading :]