Tips to Use Drow Ranger (Dota2)

• Manually casting Frost Arrows (known as orbwalking) will prevent you from drawing creep/tower aggro. This is also needed to kite and escape opponents in a bad situation.
• An early level of Silence is crucial to defend against spell-casters, although it will still be maxed last.
• With the new Marksmanship, maintaining a distance is important for Traxex now, as this will help her deal great damage to enemies thanks to the additional Agility provided. Make sure you are more than 400 units away from your enemy and kite them to keep your distance so you will enjoy the full bonus effect of Marksmanship, as the extra Agility is negated when being close to your enemy heroes.
  • As mentioned above in the Abilities section, there is now a visual particle effect that indicates when the Marksmanship bonus is active. The particle effect looks not unlike that of dry ice, and it emanates from Traxex's body. If this particle effect disappears, you are too close to an enemy, and the bonus will deactivate. This visual effect also disappears when invisible heroes are within the 400 range, so use it as an indicator for a possible gank.
• If during a team fight the enemy heroes get close to each other, using Silence in many or even all of them can simply turn the battle aside, making Drow Ranger not just a great carry, but also a powerful disabler/initiator too, if given the chance.
• When in possession of Shadow Blade, she can effectively gank by taking a shot to break the invisibility and immediately using her silence, leaving the target slowed, damaged (due to her natural high damage added to the 150 damage bonus) and silenced, being completely unable to react (apart from using items).
• Because of the removal of the bonus agility when there is an enemy hero near Drow Ranger, it is advised to avoid picking her when the enemy carries are especially mobile (Antimage, Faceless Void) or otherwise employ powerful slows that match Frost Arrow (Viper, Phantom Assassin).
• Manually casting Frost Arrows (known as orbwalking) will prevent you from drawing creep/tower aggro. This is also needed to kite and escape opponents in a bad situation.
• An early level of Silence is crucial to defend against spell-casters, although it will still be maxed last.
• With the new Marksmanship, maintaining a distance is important for Traxex now, as this will help her deal great damage to enemies thanks to the additional Agility provided. Make sure you are more than 400 units away from your enemy and kite them to keep your distance so you will enjoy the full bonus effect of Marksmanship, as the extra Agility is negated when being close to your enemy heroes.
  • As mentioned above in the Abilities section, there is now a visual particle effect that indicates when the Marksmanship bonus is active. The particle effect looks not unlike that of dry ice, and it emanates from Traxex's body. If this particle effect disappears, you are too close to an enemy, and the bonus will deactivate. This visual effect also disappears when invisible heroes are within the 400 range, so use it as an indicator for a possible gank.
• If during a team fight the enemy heroes get close to each other, using Silence in many or even all of them can simply turn the battle aside, making Drow Ranger not just a great carry, but also a powerful disabler/initiator too, if given the chance.
• When in possession of Shadow Blade, she can effectively gank by taking a shot to break the invisibility and immediately using her silence, leaving the target slowed, damaged (due to her natural high damage added to the 150 damage bonus) and silenced, being completely unable to react (apart from using items).
• Because of the removal of the bonus agility when there is an enemy hero near Drow Ranger, it is advised to avoid picking her when the enemy carries are especially mobile (Antimage, Faceless Void) or otherwise employ powerful slows that match Frost Arrow (Viper, Phantom Assassin).
• Manually casting Frost Arrows (known as orbwalking) will prevent you from drawing creep/tower aggro. This is also needed to kite and escape opponents in a bad situation.

• An early level of Silence is crucial to defend against spell-casters, although it will still be maxed last.

• With the new Marksmanship, maintaining a distance is important for Traxex now, as this will help her deal great damage to enemies thanks to the additional Agility provided. Make sure you are more than 400 units away from your enemy and kite them to keep your distance so you will enjoy the full bonus effect of Marksmanship, as the extra Agility is negated when being close to your enemy heroes.
  • As mentioned above in the Abilities section, there is now a visual particle effect that indicates when the Marksmanship bonus is active. The particle effect looks not unlike that of dry ice, and it emanates from Traxex's body. If this particle effect disappears, you are too close to an enemy, and the bonus will deactivate. This visual effect also disappears when invisible heroes are within the 400 range, so use it as an indicator for a possible gank.

• If during a team fight the enemy heroes get close to each other, using Silence in many or even all of them can simply turn the battle aside, making Drow Ranger not just a great carry, but also a powerful disabler/initiator too, if given the chance.

• When in possession of Shadow Blade, she can effectively gank by taking a shot to break the invisibility and immediately using her silence, leaving the target slowed, damaged (due to her natural high damage added to the 150 damage bonus) and silenced, being completely unable to react (apart from using items).

• Because of the removal of the bonus agility when there is an enemy hero near Drow Ranger, it is advised to avoid picking her when the enemy carries are especially mobile (Antimage, Faceless Void) or otherwise employ powerful slows that match Frost Arrow (Viper, Phantom Assassin). 

 source: http://dota2.gamepedia.com/Drow_Ranger