What metal stuff did you use Graeme? I've not used any of the specialist rod wrapping stuff, I got some Madeira metailised thread from Megs Attic in Banchory which seems to work really well. You do not need a heap of tension with the trim, backing off a bit will help.
I used a piece of thin plastic tube (inner from Veniard Scandi Tube) like a nail knot tool for my trim wraps. I taped one end of thread up the blank, laid the tube on the blank and wrapped over it and the taped end, then slid the wrapped end back through the tube as I pulled it out. When just about tight enough to spin on the blank and no more I evened it all up, snugged it against the whippings, tightened and trimmed off the ends. Bit of a fiddle but got the job done nice & even with no damage to tinsel.
Cheers
Ben