I've used lots of lights, and what I've settled on, finally, is a cheap LED headlight, with red and white LEDs. It fits around my head with an elastic band, and works well for preflight, startup, and infight use. Wherever I turn my head, I have light. The expensive models that attach to the headset, mike, or wherever are too limited. The headlight works for everything, in and out of the cockpit, and away from the aircraft. YMMV.