As Gnar, you don't have to win lane to be super effective. Just stay back, get exp if you have a tough lane (look at the matchups above) and farm with your super long range boomerang. You have to abuse that boomerang as it is probably the longest skill shot for top lane matchups it allows you to farm even while getting zoned if you catch it back because of the low cd it has. If you lose lane, don't be scared to go for a more defensive build because when you reach mid game, you will be pretty useful with all your cc and your awesome ult.

If you get ganked it is easy to jump on a minion and get your double jump which is why ganking Gnar is very tough. As for your jungler, he should like you pretty much if you get your mega you transform into a cc factory and if your jungler has damage (nidalee, reksai, jarvan) it is a summoner spell secured or even a kill! So ask for ganks!!

As you reach mid game, you will have to be pretty aware of the teamfights that happens around dragon. You will be the key of those teamfights with your tp. Ask your team to ward deep and tp in their back. The MOST important thing is to tp WITH MEGA GNAR! If you really have to tp with mini but you will not be as efficient and your tp will have to be much safer (cant tp in their backline as you will get cc to death and never land your ult). So when you see your team trying to set up a dragon farm your rage up to about 85 % and wait for the perfect time to give a few hits to minions and tp down to ult their team.

For the new top laners out there : always tp to your tower if you come back to lane, so many times I see players tp to minions, it is not worth except if you get a free kill 100% sure. Tping to tower reduces the cd of tp by a lot!

Mini
2 auto and third stack with q is best damage you can give out

Mega
R + W + Q
W + Q (doesn't show animation of you throwing boulder sometimes, can be surprising.
Q + E + R

Gnar is good to pop the banshees late game for your allied cc friends especially in mega form, just throw a rock at them, the hitbox is pretty wide and opens alot of opportunities for your teammates.

Gnar is very good with Jarvan, as you have probly heard about (the Gnarvan)you just have to ult the ennemy team into the jarvan ult and it stuns them.

I like playing Gnar with an orianna since the wombo is very easy to pull off and destructive.

He's good with anyone who has aoe cc or damage (ori, malphite, amumu, lissandra)

As for the adc I love graves since the damage is collateral and is done while you are ccing the ennemy.

Overall Gnar is a very destructive top laner if played right. I hope you learned a lot from my first guide, any feedback is greatly appreciated.

Sorry for format