We just had a tiki/luau party. Here are some things we did.
1. I carved a watermellon to look like a tiki totem dude. Got the idea from a tutorial somewhere on the web. Took a slice off the bottom to make the watermellon stand easier. Carved the designs with a knife, mellon baller, and the tip of a star shaped cookie cutter.

2. Made a spear out of a gardening hand shovel from Big Lots. Cost a whole one dollar. Cut off the tip of the handle which was too big, wrapped it in some duct tape, shoved it in a bamboo stick. This was my Tiki version of pin-the-tail-on-the-donkey. The kids and adults took turns throwing the spear into a target (hoola hoop with a honeydue mellon for a bullseye). This was a lot of fun.

3. I made Tiki masks out of oval chinet paper plates, the cardboardy kind. Cut off part of the lip, wet them quite a bit on both sides, curved them to fit them in a glass baking dish which as a little narrower than the plates. Dried them in a 200 degree oven for around 10 minutes, then they held the curver shape when removed. I cut out eyes, mouths, etc, then glued on noses. The kids had a blast painting these.

See link below for pics. I couldn't get them to post inline:
lmhs1986/tiki - Photobucket - Video and Image Hosting