As this build starts to come together you'll see why I call it "Garen : OP as ****".

By the end you have over 4000 hp, a healthy dose of armor and magic resistance, and over 250 base damage with excellent armor penetration.

It does everything.

If you farm well then you don't become tanky dps, you are a dps tank.

Armor pen reds, the choice is obvious.
Cooldown reduction blues on Garen is also obvious.
Armor yellows just for that early survivability, even if you end up laning against mages it defends you from their autoattacks and enemy minions.
Movement speed quints because people will be running from you, believe me. If you want to almost get 10+ kills then go for armor penetration, if you want to GET 10+ kills then get yourself the speed you need to close the deal.

21 points in offense, ignoring critical strike damage on the way, as your critical chance will be too low for it to matter.
9 points in utility, though you could redistribute 6 points of that into increasing your armor and mr in the defense tree.

You want the frozen mallet and boots of swiftness so that you are always more mobile than your target. Having the mallet early is key, when you run in and use your Q on an enemy they should be going ****ing nowhere.

Where you going mate?

****ing nowhere.

Run towards an enemy, activate Q for the speed boost as they will try to run. After this they should be slowed and silenced, it's time to hit E for spintowin.

During Judgement it's not enough to simply follow them around, you want to move AHEAD of their escape route while just barely keeping them within the damage range of your E.

As soon as Judgement ends you should be laying an autoattack on them to reapply the slow from Frozen Mallet.

If you feel that you are in danger at any point activate Courage, you can turn it on as part of your initiation, but I like to try and save it in case they get backup I wasn't expecting. There's no point having damage reduction before you're taking damage, it only lasts a few seconds.

Enjoy your free autoattacks due to your massive movespeed advantage, use Demacian Justice to finish them off if necessary, if you can save it then all the better.

Congratulations, you just facerolled some poor bastard.

Fatigue and ghost, why **** around?

Go roll some faces, faceroller.