Trailers are really important, without them bucktails aren't as effective I think.
You can make trailers out of many kinds of materials - in fact, rubber worms, or shad bodies could be used as "trailers."
Strips of fish belly or squid are often used as trailers.
Most people have some made out of pork rind, and the usual colors you'll see are white, yellow, green, chartreuse, red, black, burgundy, even purple.
Experiment like you would a plug.
Certain colors work better at night - like black and red and burgundy and purple.
White, yellow, green, and chartreuse are most often associated with daytime colors, but there are no hard and fast rules they can be used effectively at night too.
The fun is in the experimenting under different conditions. You're only limited by your imagination and what your best interpretation is of naturally-occurring baitfish.
You'll find some interesting consistencies. For example, whenever I drift a green porkrind in The Race (between CT/RI and the North Fork of Long Island, NY) with a white bucktail and the tide is humping, I almost invariably hook up with bluefish.

Switch to yellow and the bass start to to bite them too.
One thing, it's good to match the size of the trailer to the bucktail (not too big, not too small).