Tristana's Skill Max Order: E → Q → W
Level 1: Start Q in this lane. Try to push for level 2 as fast as you can, and if you get it, instantly vault Trist for a very good trade. If Trist lands E on you, you must land your Q or else she wins the trade. If you miss Q, back off. Her E range is the same as your AA range level 1.
Level 2: Level 2 onwards, only use your E to cancel Trist's W in mid air. If she uses W to engage on you, instantly vault to cancel her W, and then use Q on her to blind her.
Level 3-5: You must use your Q and your E specifically on Trist, try not to use them on the minions unless you need your Q to fight for prio. If you Q the wave, try doing it further away from her so she can't just jump on you. If Trist Jumps on you, you must land your Q to prevent her from getting her W reset from her E.
Level 6+: You can't use your E if you are ulted, so the goal is to kill Trist before she ults when she is blinded if you are playing aggro on her.
Push for level 2 first and start Q.
If trist Es you, Q her to win the trade.
If you get 2 first, instantly jump on her with E to punish her.
When trist is 2, only use vault to counter her jump.
Your E cancels her W in mid air, and so use E only for this.
If she jumps, E her, then Q right away to go for a short trade.
Landing Q is critical so that she can't stack up her E charges to get her W reset.
At 1-2 items you hard win all 1v1s and can one shot her, so going even in this lane is a win for you.
Positioning is key and always be cautious of her W engage. If she ever uses W, do not let her breathe for 22 seconds since it is a long CD.