Stand outside of the minion wave or behind it. This will result in him having to choose between pushing or poking you. Don’t stand in the minion wave as he will be able to push and poke with his Q or R.
Whenever Corki has his Passive, communicate with your team and ping that he’s missing. He will look to roam as soon as he recalls and picks it up.
Post-level 6, Corki will look to constantly push the minion wave. Try to match his wave clear so he doesn’t keep you pushed in. If you don’t, you’ll lose priority and tower plates.
Do not look to fight inside the jungle when Corki has his Passive as his W will deal tons of damage if he can get use it on the whole team. Fight in areas that are in the open as it makes it easier to dodge the W.
When starting a team fight, you need to engage quickly. Corki will look to delay a team fight and poke with his Q and R. If you engage and fight quickly, he will not have time to poke you down.
Do not fight when Corki has his Package ready. If he has hit up, try and wait for it to disappear before committing to a fight as it does deal lots of damage.
When Corki hits level 6, his kill pressure and pushing power increases thanks to his Ultimate R. Make sure you’re always behind at least 1 minion so he cannot push and poke you at the same time.
Corki will be a much bigger threat when he has his Package as it gives him a lot of roaming freedom which he doesn’t usually have without it. As soon as he picks up his Package make sure you communicate with your team.
Once Corki completes Sheen (Trinity Force), he will deal a lot of damage and will look to be more aggressive. Keep this in mind when trading.