There are a lot of icing tips to choose from, but for decorating cookies, you only need a few. The tips I use the most are the plain rounded tips...#1, #2 and #3 (the numbers are printed on the tips). Tips 2 and 3 are perfect for piping outlines; the #1 tip is wonderful for personalization and small detail work. It's nice to have a few larger round tips on hand for larger dots. When used with a coupler, seen in the picture, tips can easily be easily changed on the same icing bag.