I'm a novice to Tying. I've been tying Bead Head Caddis Larva and after I've made the rig from ultra wire tied it down and trimmed it I keep having the same problem. When I start to finish off the fly using half-hitches the thread snags on the end of the ultra wire and the knot's loop won't close. Usuallly this causes the threads to break off at the wire's end.

Is there a trick that I am missing? Should I try a different way of finishing the fly? How do I keep the end of the wire from snagging the thread?