[Ron Ramirez]

For what it's worth, here's what I do.

I use the 20 gauge stranded "small profile" cloth-covered wire from Radio Daze. Years ago, I decided to standardize on the 1932-36 Philco speaker wire color codes, or as close as I can get to them since we can't buy wire that has the contrasting color of tracers woven into the cotton covering - we can only purchase solid colors - as follows:

Single-ended outputs:
Green - Output plate to audio transformer
White - Output screen grid to audio transformer and one side of field coil
Blue - Other side of field coil (original color was green with white tracer)

Push-pull outputs:
Green - One output plate to audio transformer
White - Other output plate to other side of audio transformer
Blue - Screen grids or B+ to center tap of output transformer plus one side of field coil (original color was green with white tracer)
Any other contrasting color (red, yellow, orange) - Other side of field coil (original color was blue with white tracer)

I hope that makes sense.