I use Leviton devices for the most part but this technique works on P&S as well.
Assuming I did the rough and used a stuffing/switching convention that lets me readily identify what travelers go where, and assuming the colors of the travelers are different and consistent from end to end, at finish I do this...
I have a hierarchy of colors in place that in most of my cases goes black, red, white-phased black.
When installing the first switch in a 3 way set, after attaching the common first I then attach the highest color in the the hierarchy (present in that particular traveler) to the screw directly above the common. This leaves the lesser color to go on the screw opposite the common.
I then do the reverse of that at the other end of the traveler.
Both switches are installed into the box with the ground screws on the left ( the same way I install my receptacles).
When I have 4 ways in between I make sure that the colors match on their respective ins and outs. (both blacks on left and reds on right as an example).
These also get installed with the ground screws on the left.
Without dimmers or other devices that that need to be rung out to determine which 2 contacts connect in the "up" position, this technique gets all the switches down when the light is off.
I use Leviton "Togglers" to match standard switches and they have the opposite connection pattern as the Leviton switches. In this case connect them the same way at both ends of the traveler.
Occasionally I have to go back and flip a 3 way over after I power it up to make it perfect ( the best laid plans and all of that) but this works for me 99% of the time and I do it mindlessly (which probably accounts for the other 1%).
