Bridge Stick.
Placing the bridge has been one step in the build that gives me the willies. One mistake and the whole shebang is over. So, I grabbed a bit of 6mm ply, rebated a slot in the top and glued in a bit of ply to act as an orientation point. Then I marked out the scale--this one is Martin 25.4"--and put a couple stitch screws in. Filed off the points, and filed the threads facing the bridge to give a nice flat surface. Couple spritzes of rattle can lacquer and it's done.
As long as the centre is marked and the stick and bridge centre line up with the centre line of the guitar, I can't see any problems. Did one yesterday, and it's perfect.
No anxiety and no dithering

Before I did this, I looked around and the StuMac thing seems pricy, tho it's adjustable, so I wanted a low-cost alternative. I guess it could have a series of slots at the bridge for different scales, etc, but I've only made this scale so far, and reckon I'll just make another one or two if I do another scale..
Sorry if someone's done this before, but it was easy, and may help some of the other new guys here...