My sister and I threw a bridal shower recently and we made these fancy marbled tumblers. They're kinda fantastic in my opinion.

materials
nail polishglass tumblers
water + tub

step 1. fill your tub with water, and drop nail polish into it (make sure it floats).
step 2. swirl your nail polish around with a toothpick to create the marble pattern.
step 3. dip your tumbler into the nail polish. and lift up.