Stand outside of the minion wave as Aphelios does have a lot of AOE W damage. Additionally, stand away from the Tower if you’re pushed under it as his AOE autos will hit you if you’re behind the Tower.
Don’t trade at level 1 with Aphelios if you’re playing as an AP champion. He is AD based and will deal more damage than you early.
Aphelios is prone to crowd control and all-ins. If possible, try to lock him down as quickly as you can when trading to reduce his damage output. Aphelios is also super squishy and easy to kill, so he might even blow Flash when you try to engage.
Aphelios isn't very mobile so if he's running in a certain direction, he might be running towards his Jungler and you might be running into danger.
Stand outside of the minion wave when Infernum Q is active as it provides him with a lot of AOE damage and wave clear. Make him choose between pushing the wave and poking you.
When marked by Aphelios Q, don’t bother retreating too far back as his long-ranged auto from his second weapon will still hit you. Stay close to him so you can trade back.
Aphelios is very strong in team fights thanks to his Ultimate R. Try to take him down before or at the start of the team fight to reduce the enemies chances of winning the fight.
Extended trades work in the favour of Aphelios depending on his weapon setup. Try to keep trades short- preferably around his Q.
Once Aphelios gets his first item, he will be very strong and sustain very well in lane. Unless you match his damage, try not to fight him too much unless you can catch him out of position.