For some of the Rolife miniature house kits and booknooks, heat shrink tubes are involved.
I tried several methods including using a candle, lighter, matches, and a hair dryer.
The candle and matches were a bit messy with dripping wax and soot.
I found that using a lighter and hairdryer worked well. The advantage of using a hair dryer over a lighter would be minimizing the chance of blackening the tube if the flame accidentally touches the tube. When using a lighter, it’s best to let it hover.
That’s a great trick. I always do it too. In fact, I showed how I did it in one of the last kits I built. Thanks for sharing! 
I use a small torch you can use for burning sugar on to creme brulee. The flame doesnt flikker like a normal lighter and gests hotter so it easier to hold it from a distance
I have had trouble with this. I was a bit worried using a lighter would damage the tiny wires! Good to know it doesnt. The kits all seem to come with electrical tape now instead which i like better.
Yeah that also works fine as long as the wires are twisted together well enough
