Ashe

Strengths

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.

Passive · Frost Shot — Ashe's attacks slow their target, causing her to deal increased damage to these targets. Ashe's critical strikes deal no bonus damage but apply an empowered slow to the target.
Q · Ranger's Focus — Ashe builds up Focus by attacking. At maximum Focus, Ashe can cast Ranger's Focus to consume all stacks of Focus, temporarily increasing her Attack Speed and transforming her basic attack into a powerful flurry attack for the duration.
W · Volley — Ashe fires arrows in a cone for increased damage. Also applies Frost Shot.
E · Hawkshot — Ashe sends her Hawk Spirit on a scouting mission anywhere on the map.
Ultimate · Enchanted Crystal Arrow — Ashe fires a missile of ice in a straight line. If the arrow collides with an enemy Champion, it deals damage and stuns the Champion, stunning for longer the farther arrow has traveled. In addition, surrounding enemy units take damage and are slowed.

A suggested 5-lane lineup built around Ashe, based on hero partnerships and role synergy — not win rate.