To Solder or Not to Solder
I don't like solder fumes. I find that butt connectors, solderless connectors, Scotchlok tap connectors, and wire nuts all reduce my soldering needs to a minimum. Tortoises need soldering to their terminals and track needs soldering for its feeders, and LEDs need soldering to insulated wires, and frogs need flies and . . . oops! . . . wrong type of frog . . . Like I was saying, frogs on turnouts need a wire soldered to them in order to do live frog switching with the accessory switches of your switch motors, but not that much else does, if you're determined to avoid it. If a wire seems too thin for a butt connector or solderless connector or Scotchlok, double it over before crimping. If you double over a wire in the tap hole of a Scotchlok, make sure the folded over wire end faces the tap cutting blade.
Often when you're connecting up control panel switches you end up needing long wires with many tap wires connected to them. There are several ways to do this: (1) The easiest and fastest way is to use all #18 stranded wire and a handful of Scotchlok 905s. Cut your run wire (the long wire) and your tap wires (the short pieces) from a spool of #18 stranded wire, get out your long-handled tongue-and-groove pliers for easy leverage, and make sure that tap wires are inserted all the way into the tap hole before crimping. (2) Solder or wire-nut a bunch of #22 to #26 tap-wire ends together along with the end of a run wire—or even use a large crimp-type terminal connector or butt connector; if any bare metal on a connector or solder joint is exposed, cover it with electrical tape. (3) Either use bare wire with heat-shrink tubes in between connections or use insulated wire with ¾" lengths of insulation stripped off, and then either solder (not recommended because then you have to tape each joint and a crimp-on connector is easier to deal with and doesn't need tape that may come loose some day) or connectors on the bare wire sections.
In some cases, the run wire can be strung with larger butt connectors that will hold both the run wire and added tap wires. But for smaller butt connectors, simply double over the ¾" bare wire section so there's now a 3/8" end to insert into the connector and crimp. Or if you're using the solderless connectors that get pushed onto the terminals of small toggle switches, you may again bend over the bare wire section and crimp it into the connector.
These methods give you a way to send lamp power, throttle power, Tortoise power or uncoupler power from source to target with one wire that branches out only when it's near the target cluster. I do this in addition to utilizing bus wiring schemes for overall layout wiring, which means that I often tap from the bus with a Scotchlok and then I tap from this tap with other Scotchlok-connected taps. If I had bigger current loads to deal with, I'd be concerned with the weakness of so many connections from source to target, but with the tiny current loads, involved, there's no problems.