I pre-assemble/dry run the stanchions' fit to the triple trees. I confirm that the tapers in the upper tree are clean, paint free, and well matched to each stanchion. I also do this with the interior clamping area of the lower tree.
If you want to be obsessive, check the clamping area and the taper/cone with Prussian blue.
I prefer top down and as I am snugging and aligning in stages, I bump the front end into a wall to make sure it is settling.
I've seen fork tubes that were knurled in a band at the clamping areas. I imagine that they were stripped, knurled, and then re-chromed.