3M’s Scotchlok brand quick connectors are incredibly handy for loose wiring jobs. We tested their UY2 “butt” connectors, intended to join two conductors end-to-end, but the series also includes cap, tap, and even four-way connectors in various gauges. To use, just insert the cut ends of the wires, aligning them with the internal metal slot terminals, and push down on the tab to make the connections. 3M only warrants their published specs when the deal is sealed using their specially-designed E9-Y hand crimping tool, but, between you and me, we had pretty good luck with regular pliers, too. Much faster, better looking, and (we expect) more durable than wire nuts.