Place the softened butter in a medium bowl, cut into pieces and add a pinch of salt.
Add your herbs or flavorings and use a rubber spatula to fold and mix until the add-ins are completely incorporated and evenly distributed throughout the butter.
Transfer the butter to a piece of plastic wrap. Shape and roll it into a log about 6 inches in length. Twist the plastic wrap at the ends to seal. Refrigerate for at least 2 hours before serving to allow the flavors to meld. (Alternatively, you can transfer the butter to a small bowl or ramekin and cover with plastic wrap.)
Notes
Shaping: The most common way to shape compound butter is in the long, as described above. You can also store your compound butter in a butter dish with plastic wrap.
Storing: Fresh herbs in compound butter last about 1 week in the refrigerator. If you made compound butter without fresh herbs it can keep for up to 2 weeks in the refrigerator.
Freezing: For longer storage, keep your wrapped compound butter in the freezer for up to 3 months.