I'm not sure what my 1 rep max is. Now that I think about it, I haven't maxed out in about a year or so.
I currently Flat Bench about once per month and when I do, it is generally the first movement in my Chest workout. I much prefer to start with an Incline movement though.
A typical flat bench workout for me now looks like this:
Warm up rotator cuffs first
135 x 10-20 reps for warm up
225 x 10
315 x 10
405 x 5-8 reps (depending on strength that day) then dropset to 315 for max reps, followed by a drop to 225 for max reps, and finally a drop to 135 for max reps.
Weight is 253 right now.