This is my carry build for Tristana. The point of this build is too tear through your opponents early with Black Cleaver while not attack horribly slow as if you would rush I Edge or something else. Tristana has amazing auto attack capabilities due to her passive therefore making Black Cleaver very very effective on her.

The rune set up I use has armor pen and attack speed to maximize damage and magic resist glyphs to help out in the laning phase against casters.

I always take a 22/0/8 Build on tristana, using flash and ignite for summoner spells and taking cd reduction and attack speed in offense.

My item guide is a little different than most according to the face that tristana has very poor attack speed early game until you get her Rapid Fire leveled up. Opening with Black Cleaver really maximizes the effect her passive has on laning(increases her auto attack range) because it can stack the armor reduction before ingaging. It also helps with her attack speed issue without taking away any massive damage output from her. Late game Last Whisper and F Mallet really maximize her damage output and get her alot more durability while making all opponents not be able to run from her.

The early laning phase is crucial for this build because you must farm last hits amazingly. 1 point in your e at lvl one then w on lvl 2 and 3 followed by your q then maxing your w is always priority. It will allow you easy farm from your e while being able to last hit or harass with your q and w.