This is a experience build made by NightBlue3, a twitch streamer and daily youtuber. He likes to choose champions rare in the jg and even the ones that you think thats impossible to do, and he make it happens. He's a lovely guy and deserves lots of love, if you had a good game with this build, why not go to his channel to give him some support, hm?

Follow this till 6 level, by there, you can up things at your own.
Its ok to start with the Judgment one tho, but the Decisive Strike will help you with the lonely ones, but its your choice, don't be scared to try.

The farm with Garen jg is normal, you dont really need blu tho, so why not help your team giving them some mana reg?
It's really easy to farm with him, even in the early game, you can wash minions and all with some spins.

Garen can be good at 1v1 and 1v2, his ultimate is a instant kill, so just be sure to spin on the haters and do some damage with the Decisive Strike then you can ult one and take down the other one easily, even if you're in a lower level than them.

If you're in a battle and losing a lot of health, use the Decisive Strike to run and walk a little to regenerate your life. Why that? Well, Garen has a really high regen porcent so the only thing that you need to do is get off the battle for a few seconds and then come back with almost full HP! Pretty neat, right?