2 Flavor Sticks are enough for 4 pieces of candy (one cube). You can play it safe by using two of the same flavors, or you can go crazy and combine two flavor sticks that maybe (or maybe not) taste great together! Do yourself a flavor and get creative!
Remember you always need 2 Flavor Stick PRODUCTS for 1 Cube PRODUCT. Read more about Piñata surprises under How it all works.