A kit everyone who wires should have.
I've put together a kit filled with different number terminal Weatherpack and Deutsch connectors and accessories from MSD.
Whenever you're working on a wiring project, especially something custom, it really pays to have more than you'll need in stock at home. Runs to the store cost money and time but even more importantly, frustration. I usually get burnt out on a project when I've been making silly runs to the store to get things I should have had.
Of course you should always have the regular butt, spade, and eye connectors at hand but it's nice to have the specialty stuff too. These multi-terminal connectors give a really clean look and easy-disconnect to any part of the harness.
Visit MSD's website for specific product information.