Well for the ends that connect to things I would use a crimp on insulated ring or spade terminal of the correct size, other than that I would definitely eliminate any other splices in the system if possible (Other than wiring to the motor leads if you can not go directly to the motor) and solder directly to the motor terminals.
We have never had much of a problem with the crimp on insulated connectors but if you wanted to be super careful you could solder them too then shrink wrap around the outside. Make sure who ever is doing the soldering has some sort of idea what to do, I don't want to even get into some of the soldering I have seen.
