About a year back I stumbled across these cool products that are a heatshrink sheath with a metal ring coated in low temp solder inside. They made all of my wire joining a million times easier. Just strip the end of two wires, push them into the sheath and blast them with a heat gun for 20 seconds until the ring contracts into a crimp and the solder flows onto the wires. Better physical and electrical connection than a crimp, with none of the futzing that comes with soldering and sheathing.
These are so cool! Do you have a link to buy?
Edit: Found them! These are crimpless solder sleeves. Crimpless Solder Sleeve Heat Shrink Variety Kit - 90 Piece