Try to fire Enchanted Crystal Arrow in the same direction enemies are moving, so it is more likely to hit.
Volley arrows are blocked by the first enemy they hit, so keep your distance to avoid having them all absorbed by enemy frontliners.
Hawkshot reveals units in brush. If a team fight is occuring in the jungle it can give you a significant advantage.
Ashe has very few defensive options, and she's a good target to gank.
Using Cleanse to remove Enchanted Crystal Arrow's stun can turn a fight in your favor.