Fabulous tutorial, thanks much!
I've been doing much the same thing for years using Microscale Metal Foil Adhesive. I've long suspected the product could be bought cheaper in a craft store if I knew what to look for, so MANY thanks for that!
I apply it using a finger, just smearing it on thin. No brush strokes, no loose brush hairs, nothing to clean up but my finger.
I also found that the glue wanted to "bead up" on the foil, leaving holes in the coverage. I found this could be beat by roughing up the backside with a Scotchbrite pad. Doing so acts something like a primer, giving the glue something to grip onto and/or breaking up its surface tension. Solves the problem completely.