We like to start with unsalted butter so we can add coarse, kosher salt. And as far as how to serve it, we like to shape it into a log, roll it in plastic wrap or parchment paper, and throw it in the fridge (or the freezer if you need it sooner). Then you can slice it and have nice, round patties.
A little coin-shaped nugget of herb butter is perfect for corn-on-the-cob. While the butter melts and drips into the crevices between kernels, flecks of green scatter on top. Beautiful. But it's also nice to put a pad on top of a simply grilled piece of meat as soon as it comes off the grill or out of the sauté pan.
Or stir it into mashed potatoes... spread it on fresh bread... serve it in a bowl with some radishes as an appetizer...
How do you use herb butter? What are your favorite herbs to add?