Tristana Runes explained
There's one set of runes for Tristana on patch
11.19
that is the clear favorite for LoL players and pros alike. The best Tristana Runes on the position 
Adc are Domination as the primary path and
Precision as the secondary path with a pick rate of 60%. Besides runes you should take a look on Tristana Build and if you are interested in pro matches take a look at Tristana Probuilds. If you want to discuss
Tristana then you should visit the champion subreddit.
Primary path on Tristana
Domination improves burst damage and assassination tools on Tristana. Most of high elo players – and our LoL pros in the the major regions – have agreed that
Hail of Blades is the best keystone rune to run on
Tristana. This keystone rune helps you to win short damage trades in your lane by increasing your attackspeed at the beginning of a fight. This is usually followed up by taking
Taste of Blood,
Eyeball Collection and
Ravenous Hunter.
Taste of Blood heals Tristana as soon as you damage an opposing champion.
Eyeball Collection is next up. This grants the user additional damage with every killing they score.
Ravenous Hunter is the final rune of the
Domination path. This rune gives some survivability during short fights and damage trades during the laning phase. The additional health is nothing to scoff at and can mean the difference between winning or losing a battle.
Secondary path on Tristana
When it comes to your secondary path, most
Tristana players prefer to go with
Precision.
Precision improves attack and sustained damage on Tristana troughout the match. On the
Precision path, the best runes for Tristana are
Legend: Bloodline and
Overheal.
Legend: Bloodline gives life steal, which aids in winning damage trades and fights in the later stages of the match.
Overheal converts healing in excess of maximum health of Tristana into a shield, which provides additional safty and tankiness.