I use Speedball super pigmented acrylic ink from Hobby Lobby, the cheapest calligraphy pen they have with a good, extra fine point. The ink in the picture is at least 5 years old.
I dip the pen in ink, make a few lines on a piece of cardboard to unload the pen a bit and get it making fine lines without any blobs, and start lettering.
The smoother you have the surface you are going to letter the better the pen will write. Rough finishes will cause the pen to skip and make a mess. I have about 3 coats of finish on a bow before I start lettering and put a couple more coats on over the lettering.
It is a rare bow that I can letter in one try. I keep a wet paper towel close at hand to wipe off my goof-ups so I can start over. My hands are pretty arthritic from excessive draw knife use over the years and don't work too well for neat lettering.