Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Hi (future) Garen player
At the moment Garen is one of the most OP (OverPowered) Champions in the game.
His ultimate is feared by everyone. The best way to play him (according to me) is as a tank.
Sunfire capes realy boost his hp and damage output and above that he gets a ****load of armor. If your enemy team is full of physical dps (such as Yi, Ashe, Udyr, TF and many more)
You might consider to get a thornmail instead of another sunfire cape. (If you have absolutly no magic damage in the other team skip your force of nature instead)
Mercury's threads are very good against cc. So if you dont have any good cc in the other team get other boots ! (BoS or Ninja tabi i recomend)
Engage in combat:
Since you are a tank you should initiate (dont forget to use your courage skill if they gonna nuke you). Just spin around in the enemy team damaging a lot. If their main dps doesnt die fast enough use your ult when you can finish him off. (I usually like to kill cho'gath or mundo instead since they are a pain in the *** to kill but nevertheless their main dps is more important).If you continue just run near to people and hit them when you can. Always use your Jugdement whenever it is up[ in a fight. It boosts your aoe damage which will do more damage then just a basic attack.
HOW TO USE YOUR ULTIMATE PROPERLY:
Level 1 : 175 damage plus 1 per 3.5hp missing.
So basicly just use it when your oponent has 2/9th of his max hp. It will kill him unless he has a ****load of MR.
Level 2: 350 damage plus 1 per 3hp missing
Use it when you enemy is on 1/4th of his max hp. (also insta kill)
Level 3: 525 damage plus 1 per 2.5hp missins
Use it when your enemy is on 2/7th of his max hp.
Sure it does more damage but it gives you some space in damage since you usually dont look at the enemy's MR.