Tips to Use Luna (Dota2)

• Luna and Night Stalker complement each other well; as Eclipse causes day to become night and Darkness gives both of them a very long vision range.

• Early points in Lunar Blessing will make last-hitting creeps easier. At any rate, make sure you have a single point in it before the first night as only one point is needed for the full amount of vision it bestows.

• Early points in Moon Glaives will push the lane. Moon Glaives is commonly not skilled at all until the laning phase has concluded.

• Extremely unusually for a hard carry, Luna gains significant killing power with a level advantage, owing to Lucent Beam and by extension Eclipse.

• Lucent Beam's cast range is gigantic. Use it to pick off fleeing heroes.
  • Bear in mind Eclipse's range is much smaller than Lucent Beam's.

• Under almost all circumstances Luna should be paired with a disabler for her laning phase; as aside from her high movement speed she has absolutely nothing to help her avoid ganks or kill attempts.
  • It takes significant skill and knowledge of the game to solo a lane with Luna. Her very small attack range and purely damage-oriented skillset mean she is extremely easy to kill. Even then, it is recommended to have ward vision and easy access to team backup for her to be successful in a solo lane. The advantage of running a solo Luna is that it is essentially high-risk high-reward. A Luna with level advantage doing well can easily set the momentum of the game in her team's favor. 
   

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