Against galio, When Galio charges towards you, try to disengage as quickly as possible. If you let him get close, he will look to engage with his E and then taunt you with his W.
 
As soon as Galio goes missing post level 6, ping your team as he may be looking to roam with his Ultimate R.
 
If you’re a ranged Support, use your range advantage to harass and poke him down whenever he moves forward to secure minions on his warding quest. Against galio, When Galio charges you, try to disengage as quickly as possible. If you let him approach, he will seek to engage with his E and then tease you with his W. As soon as Galio loses the level of position 6, ping your team as he might seek to wander with his Ultimate R. If you are a varied support, use your range advantage to harass and bring him down every time he advances to secure minions on his pupil quest.