If you are using dark colors, black thread works well. Some threads come in various shades, if you want to use one, decide which color is the dominate hue in your pattern and match it with the appropriate thread color. However, keep in mind that if you are using seed beads your pattern with be a bit wider than it is tall. Count the number of rows in the width of the pattern and then add one more to it. This is the number of warp threads that you need to load onto your loom.
Seed beads come in many shapes and sizes.
For beadweaving, there are two types of beads. Seed beads and Delicas. Seed beads have been around for many centuries. They are the beads that the English traders used as currency with the American Indians, Africans and other colonies. Most are imported from either The Czech Republic or Japan.