Also keep in mind the number of connect-disconnect cycles which will loosen up a connector very quickly if it wasn't design for that purpose.
For hobby project use - I have a box full of various 0.1" male & female pairs with separate pins, a few 5mm 'power' style 'Phoenix' pluggable barrier connectors, and another box with multi-way IDC variations - and the mandatory spades & associated oddballs.
A good selection of heatshrink, and a sheet of plastic/mylar is always good to cut & slot in-between conductors in tight spaces
Add in a box of various cable-ties, p-clips, some hot glue, and 5-minute epoxy - and you're done.
Oh - and a decent selection of M2.5, M3 and M4 star-washers, nyloks, nuts & bolts.
This setup will connect almost anything to anything - assuming you have the right wires or cables (that's another page!)