Use wire protectors with crimp beads and Soft Flex wire.
Wire protectors (also called “wire guards”, “cable thimbles” etc.) are relatively new on the market. They offer a convenient way to protect your thread or beading wire (such as Soft Flex) where it attaches to the clasp, making a professional looking finish in the meantime. Each end of its horseshoe-shape is tubular and the arc of the piece is a channel. This “horseshoe” is essentially the loop that your clasp hangs from at the end of your necklace or bracelet.
When you are ready to attach a clasp to your piece, and after you have added your crimp bead, thread your wire up through one end of the wire protector. Then thread the wire down through the other side. The wire will lie in the channeled section of the wire protector (the arc of the “horseshoe”). Slip your clasp into this loop and thread your wire back through your crimp bead, crimping and finishing as you would normally.
Related: How to Use Wire Protectors (pdf file)
from The Bead Scoop Vol. I Issue 2, Sept 2007