- Level 1 and 2 Are Your Friend
Ryze has a terrible early game. He has a small mana pool and his abilities cost a lot to cast. He doesn't have a lot of damage without all three of his abilities either. If you're playing a champion that can take advantage of this, do it.
- Pay Attention to His Passive
Ryze can only really 'omg wtf' you if he has his passive up. If you hard cc him during it or stay away from it when he's about to get it his damage is significantly lowered.
- Try and Coordinate Ganks With Your Jungler
Ryze is immobile. Almost any jungler can get behind him and force a summoner spell if played correctly. A lot of Ryze players won't be too keen on going for engages if they can't get out in a sticky situation.
This is more 'troll' than other methods, but Galio's sole purpose is to shut down mages, especially immobile, closed ranged mages. His ult is basically a silence and there is no way that Ryze can cancel it.