The best hand tool is a Japanese mortar and pestle called a suribachi <<insert photo>>, which consists of a ceramic bowl with interior ridges that facilitate grinding and a long wooden pestle. Suribachis come in several sizes and are inexpensive; don’t bother with a small one, as then you’ll need two. A large one is ideal for grinding both large and small quantities of ingredients.
Butter is a wonderful addition to pesto; it adds a rich voluptuous quality but can be omitted if you prefer.