Early game, you need to spam Crescent strike to lower their health until you got them at 3-4 bars. then you Moonfall them in and immediately turn on pale cascade. Follow them when they run and keep spamming them with crescent strike.
After you have your ulti, the strategy changes a bit. Start with crescent strike then jump to them with your ulti. Once there turn on pale cascade. When they try to run away moonfall them in. Try to save your ulti until you have moonlight on them but if your cooldown on crescent strike is still going and you think the ulti will result in a kill, then use it.

How to use her abilities:
-Crescent strike: When enemy is stand still, focus on hitting as many things you can on the way to them. When enemy is on the run set the attack in front of their running path so that when it does come around they run into it.
-Pale cascade: Use when you are in melee range of enemies for the orb damage. This is best done after using moonfall or lunar rush.
-Moonfall: ONLY USE IT WHEN THEY ARE RUNNING AWAY!!! Pull them back in for the kill.
-Lunar rush: Try to only use it when you have moonlight on them but don't be afraid to jump in for the kill if their health is low enough.

I focus on crescent strike doing the damage early game, then late game it becomes a balence between crescent strike and pale cascade doing the damage, while moonfall and lunar rush keep you in fighting distance.

This is a balance between off tank and AP. Starting out with health and then working in more damage.

**Alternate item choices**
-May want to replace murc treads with ninja tabi if is an AD focused team.
-May want to replace Force of nature with Thorn mail for an AD focused team.

These spells are good for keeping you in battle and helping you get away. Consider using flash to get away or to get catch up to enemies that are getting away.