I use one with temp control for that very purpose. I don't know that I do it the best way, but I prefer a very hot iron so I can get on and off in a hurry before the heat spreads. Mine goes up to something like 972 degrees at the hottest and that's what I use. I also use the lowest melt point solder I can find.
We all have our own procedures for connecting to the track, but here's what works for me. I drill a tiny hole next to the rail where I want the piece of bare wire to drop through the benchwork. Clean the spot where you want to fasten the wire to the rail so the solder will easily adhere. I cut a piece of bare wire about 6 inches long, make a tiny hook to clip on to the bottom flange of the rail. Tin the hook with solder, then insert the wire into the hole and work the hook over the rail flange. Touch it with the soldering iron to solder it to the rail.
Sometimes it works very fast, sometimes I don't get it soldered the first time, one just has to develop a feel for the process. I frequently hold the wire in place during soldering by reaching under the layout with one hand. The wire doesn't get hot as the benchwork acts as a heat sink.
When the bare wire is solidly soldered to the rail, I mount a small barrier terminal strip and fasten the feeder wire to the terminals. At that point, I have a good solid, no nonsense place to connect any sort of feeder want to use. That wire, would, of course, be color coded to keep the two poles or phases correct. The wire up though the bench is bare.
I'm probably a little old school on using terminals strips instead of the more recent clip connectors, etc., but I want some old fashioned solidarity in my connections that I can see, feel, touch and measure if necessary.