Drow Ranger

Use Frost Arrows frequently to harass as you don't pull aggro but also to secure lasthits with extra damage.

Be careful of allowing the enemies to get to close during laning stage, You are especially vulnerable when your support is pulling the lane.

Multishot does the most damage when used point blank as all the arrows will hit the target.

When in trouble, you can potentially Gust and teleport out.

Drow loves agility stat as it gets further increased by Marksmanship.

Drow is all about positioning. Avoid showing yourself too early in the fight and maintain distance.

Avoid buying evasion and miss chance piercing items as Marksmanship already does that for you on proc.

When you get your aghanims scepter online you're single target damage increases dramatically.

Drow Ranger is slow and has low armor. Look to harass her as much as you can on early levels.

Avoid being in point target range of Drow Ranger when she starts channeling Multishot

Drow Ranger's Gust and Multishot have cone shaped area of effect. If you are on top of her look to side step or run past or through her when she uses those spells

Gap closing items are good against Drow Ranger as she is a glass canon hero. Note that her Marksmanship is disabled when you are within 400 range of her

Halberd's ability is amazing against Drow Ranger as it disarms her for 5 seconds. Keep in mind that Marksmanship procs pierce through evasion (true strike)

Drow Ranger should be a priority target in team fights as her team loses Marksmanship aura when she dies

Use Smoke, to wrap around Drow Ranger and kill her