This wouldn't satisfy a "neat freak", but what I do is drive a screw into the benchwork or the underside of the roadbed, leaving about 1/4" of the shank exposed. Then I run a few turns of wire--24 gauge insulated wire, solid not stranded, which I get from old telephone cable--around the screw and form a loop with it, then a few more turns around the screw. I can make the loop any size that's needed for whatever wires need to be secured. It's crude, but it's fast and cheap! Lots of people just seem to leave wires tangled and hanging loose, which looks like an invitation for things to get damaged. And when that happens, it'll be a nighmare to fix.
I remember getting a tour of The Model Railroad Club Inc, in Union NJ. They had their wires neatly stapled to the underside of the layout and running at right angles. I thought it was a bit much, but they truly are neat freaks.