I saw a baking trick in the latest Martha Stewart Living that I wanted to try. It was a recipe for pretty, swirled meringue cookies. (Meringues are kinda like macarons, minus the almond flour.)
For a while now, I've been trying to figure out how to make multicolored macarons without totally screwing up the batter. When you add too much food coloring or fold the batter too many times, you get messy macarons. I want pretty macarons.
Anyway, Martha's tutorial said to paint stripes on the inside of the pastry bag with gel food coloring before you fill it with your batter. I tried it, and it sorta worked. They weren't pretty & swirled like the meringues in her photo, but they were definitely different, and colorful. I think the green food coloring I used was too dark.
You can be sure I will try this trick again. And again. And again.