'Thread off the spool and into the needle's eye' also works for me. In fact, when I'm hand quilting/appliquing I thread several needles onto the thread still attached to the spool then knot the free end. When ready to use I pull off the length of thread I want to use, cut it and reknot the thread attached to the spool which secures the remaining needles previously threaded. Usually much easier to thread several at a time than later threading one at a time when the lighting might not be as good and your steadiness is A-1.