Seeing as Luna grew up in a cold climate, she's almost always wearing an outfit that keeps her mostly covered, so don't expect to be able to tie her in anything else without having a CCR ready. She dislikes being taken by force, but there's a good chance that she'll agree to go willingly. If her outfit remains unchanged, bind her legs under her skirt and focus attention on her sensitive feet. If her outfit is changed, go with something that focuses on her hips- like a bunnygirl suit- and enjoy them or her spine. No matter her outfit, give her a gag that emphasizes her hair and let it loose.