You can recast the spell over several nights. Some people will charge the candle with energy, light it for a few minutes then snuff it out. Repeating the process for a week and completing the spell on the full moon as it is believed to put more energy into the spell.
Not too sure what your hair question means. Moonlight can charge it but I would recommend doing so depending on the spells desired outcome. Casting by the moonphase is a good idea, I probably wouldn't charge it with moonlight.