Just a couple of other notes on the party. We served pulled pork and a variety of sweet goodies. The food was a hit.
I set up a scavenger hunt type game where participants had to find 8 tikis hidden around the yard. Each tiki had a word on it (tiki, hula, hot, bones, etc.) Once they had found and written down all 8 words, they could turn in their paper for a prize. The game was a hit and was very low maintenance for anyone not wanting to man a game station all night.
I played a mix of luau/hula type music and tribal drumming. The kids loved to dance during the hula parts and the more dramatic drumming worked well with the tiki totems set up around the yard.
This was a fun theme that was pretty easy to do. Existing Halloween decorations could be incorporated by dressing them up. I thought my standing zombie looked quite dashing in his Hawaiian shirt, visor, and leis!