I've made this countless times in many different ways: savoury, with lots of thyme, oregano, sage; spicy, with cayenne pepper, red pepper flakes, etc.; Experiment with spices and combinations, like roasted garlic or roasted red peppers. Yum! You'll never go back to store bought!
Compound butter is simply butter with an added flavor or two mixed in. It's not just like buttering an item and then adding a sprinkle of the flavor - compound butter becomes a unique flavor unto itself. You can put these on pastries, meat, pasta - anything you like.