The beauty of this tip is how versatile it is. When making compound butter, you can add just about anything you want. Mix a little juice and zest from a lime or a diced chipotle in adobo into the butter before freezing for some Southwestern flair. Or, like Greenhead suggests, some finely chopped herbs of your choosing. In fact, compound butters are a great addition to many dishes, including atop a freshly grilled steak.