Rengar's Skill Max Order: Q → W → E
Level 1: Do not cheese in this matchup. Avoid the bushes level 1 because Rengar will destroy you. Stay far back from the bushes on the bottom side of the lane so that he can't jump on you. If he jumps on you level 1, instantly E him because it cancels his dash and damage.
Level 2: If Rengar jumps on you level 2, throw Q on him before he walks back in the bush. If Rengar is blinded when he is in the bush, he can't jump on you. When nearsight ends, he will leap, and now use E to cancel this one before running away from his leap range.
Level 3: You ideally want to shove Rengar under tower if you can. If he is under tower he can't bush cheese. Or, let Rengar push against you if you are afraid of being ganked by jungler. You do not want the lane to be in the middle because this is what Rengar wants for him to cheese you.
Level 6: If Rengar Rs you, spam E when he leaps out. If you do it quick enough, you can cancel his Q leap and bring you to safety. This is hard to do, but it is possible.
Play the lane away from bushes. Ideally, shove him under tower or let him shove so he can't bush cheese you.
He wins if the lane is neutralized.
If he is in bush, E his Q leap, and then when he walks back to the bush, Q him before he enters so that he can't get the second leap off.
This combo is essential to take good trades against him, so only walk near the bush with your E up.
If you go even in this lane it is a big win for you because you outscale him if he isnt crazy fed.
If rengar cant one shot you post 6, you hard win the fight.
Thats why i like bone plating and plated steelcaps in this matchup.