One topic I see come up frequently online is feeders. My general approach has been the same from the start - I don't want visible feeders, so to me the only option is to solder them to the bottom of the rail. Yes, I've seen people do them to the back of the rail, but that assumes you never take photos where that side of the rail is visible. You also have to be more careful not to create a problem when soldering to the inside of the rail.
As for attaching them to the bus? That's a different story.
Since I've basically re-laid the east and west sides and Berlin Line, and of course have the new Whiting St Yard and staging, I have a lot of feeders to drop again. Chris will be coming over to help with a lot of them, since this approach is tougher for tracks farther from the front of the layout, but it can be done without help.
Feeders to the Rail
First step is to drill 1/8" holes for the feeder wires. I do this so the feeder will come up behind each rail. I have a small piece of Masonite with a larger hole that I drilled that I use to protect the rail so I don't mark it with the drill chuck. I've used my Dremel or a regular drill to drill holes. Either work. In this location the benchwork is 1" foam on top of OSB.
The bus is 14 gauge, and the feeders are 22 gauge bell wire. I would have preferred all the same color, but this was what I could find and as long as red is connected to red I'm good.
I then push lengths of the bell wire through the holes, strip a small amount (maybe 1/4") and bend the tip over. As you may have noticed in other pictures, I've been doing this step around the entire layout, then I'll go back to solder them.
I use a no-clean non-acid flux on the wire and tin the wires with thin, silver bearing solder. Make sure you preheat your iron. I use one of the brass wire cleaning sponge to clean the tip once it's hot, and before I put the iron back in it's stand.