I've done my own electronics since 1989. I am no expert, but there are a few fundamentals. Keep the work and tip clean. Makes for great heat transfer. The dirtier it is, the longer you have to heat, the more chance something will burn. Oxides are bad, most sandpaper is Al oxide. You will be loading the surfaces with oxides if you use it.
I have an old radio shack with a low/high switch that I transplanted a Weller pencil style onto. Works great. Butane works great too but has a bigger heat affected zone. Ive used that a lot on my roof for Ham radio solder joints.
A lot of the stuff we do is very low voltage (like pickups) so any lousy joints will affect the sound