So, I change out the whole assembly on both of my front foglights and I've thought about now using these old assemblies, replacing the burnt out corroded bulbs and mounting them either on a rack or on my back bumper or something.

My question is, how do you CORRECTLY go about wiring in aux lights? I've searched around a bit and seen a bunch of back and forth threads, but there seems that there's a very obvious right and wrong way. If there's an existing thread that covers this, just point me there!