If it's not too steep (less than 30 degrees), rapping down a static line anchored tightly at the bottom will keep you close enough to bolt. You can often find pin placements, hooks, or somesuch as temporary anchor points to hold you in enough to reach the rock.
Anything steeper seems to me simply a pain in the ass. Sometimes you'll reach as far as you can and drive a temporary 1/4" from which you can then reach the permanent placement. Or a pin, or a toe-hook(!). Hard steep routes'll often have bolts a bit closer together, just so you can work the cruxes without having to bump up 20' after each failure (us sportos are into ease and convenience).
I've heard of long horizontals (Maple Canyon) being bolted with the aid of a long 2 by 6; place your first bolt, attach 2 by 6, shimmy out 2 by 6, place next bolt, etc. pain in the ass still, from the sound of it.
I agree, SC, those are good techniques. Having put up a number of sport routes myself, other options are:
carry a stick clip with hooks, stoppers and cams that can be taped to the stick for placements to get you to the next (lower) section of overhang.
Have partner on ground to pull you in "fireman" style. This can be aided by pieces placed above ground level, or aiding/climbing up to the base of the overhang and placing a directional to feed a fixed line or rappel line.
Partner can also lock you off for ease of placements.
