As a Tristana Main, I can tell you... 100% of the times you die, it's your fault. Tristana should NEVER die.
You have a push and a jump. If you get caught, you were not well positioned. If you get flanked, you don't have good ward/vision control.
Another problem is that people don't seem to understand that you have literally NO BUSINESS picking fights during the early game.
It's funny/sad when people expect Trist to trade successfully early against Lucian, Corki, Graves or even Jinx.
If you are picking fights early as Tristana, then don't be surprised that you aren't getting anywhere. Your job is to farm and get to that IE+PD power spike. THEN you can start taking fights, but pick them well. The problem with Trist is that people don't seem to be aware of her strengths and weaknesses.
Respect the enemy lane at the early game. Keep your distance during fights, and NEVER use your W to go in, unless all enemy team is around 25% HP left and you are doing janitorial work, cause otherwise, the moment you go in with Rocket Jump, you are making a statement to the enemy team: "Here, my escape is gone. Kill me"
You also shouldn't be rushing to take out the outer towers. If you are winning lane, don't kill the tower, just stall it. It's free farm for you. if you super rush it, it'll be harder for you to farm and you'll never get to your power spike in time.
She also favored by ASPD, so go for the
After IE and PD, before
. They nerfed her ASPD because it's so good on her. Consider also Blue ASPD runes. MR will do little for you if a mage assassin tries to go for you, but the extra ASPD will do wonders for you.
You also must be aware of your team and support. You can't play the lane the same having a Thresh than a Janna. You can't fight the same way with a Sejuani jungling than with a Lee Sin.
No, the thing with Tristana is that she's in the same place as Diana right now. You have to know the champion very well and know what you are doing to be effective.
Learn the map, respect the early game, farm up, don't rush the first tower and keep that jump to always remain safe.