Back before I finished the guitar, I put a piece of 150 grit paper on the top and rubbed the bridge over it so that the underside of the bridge would have the same slight dome shape as the top.
Here's the top with the bridge mask removed.
Check out what the wood used to look like, before I dyed it, pore filled it, and applied shellac.
My bridge gluing jig, has a tiny bit of play in it, so I put this tape down to help me place the bridge, and also to catch glue squeeze out that will ooze outta there after I tighten the screws.
And here's the bridge gluing jig I made. I put a phillips screwdriver in those screwtops, and then reach inside the guitar and tighten the wingnuts inside of there as tight as I can get em.
Wipe off the squeeze out, remove the tape, and wait a couple of days.