Against tristana, Her E and Q makes taking down turrets a piece of cake. Avoid letting her get free shots on your turret since the tower platings will give her a gold advantage over you.

Avoid extended trades with Tristana whenever her E is on you. The more auto-attacks she hits you with- the more damage you will take. 

Tristana will often use her W aggressively. If you’re strong and have good all-in, you could try to trade back with her and use her mispositioning to kill her. Take a quick glance at the minimap to see if her Jungler is nearby before committing to the fight though. Against tristana, Her E and Q bring down turrets a piece of cake. Avoid letting her get free blows on your turret as the tower trays will give her a golden advantage over you. Avoid prolonged exchanges with Tristana every time her E is on you. The more she hits you with self-attacks with- the more damage you will take. Tristana will often use her W aggressively. If you are strong and have good all of it, you could try to trade with her and use her bad position to kill her.