Unless the lamp bead you are using is very small and light (this is possible), you need to realize that lamp beads are heavy and have big holes. You have to be able to enter the beads on the amulet bag to attach it, so you need thin thread like Nymo D or O, or Silamide. This means multiple passes through the lamp bead to support its weight. The big hole is a probelm also. Delicas or 11/0 seed can be swallowed by the big hole in a lamp bead. You need to use a buffer bead like a crystal or a 6/0 or 8/0 seed bead between the lamp bead and any smaller beads like delicas that you are using for attachment or in fringe. One of the best ways to use a lamp bead on the bottom of an amulet bag is as a tassle. See the bag I made in 1995 that I call The Big Bang for a bag of this type.

A black crystal is used as the buffer bead. See below for a closeup of the lamp bead.

This lamp bead was made by a local artist and I can't remember who they are. I bought it a bead bazaar at the Goldstein Gallery at the University of Minnesota.