Mirrors (so I can see): one on the end of the handlebar plus one on the helmet.
Reflectors: one big one over the fork bridge, a smaller one on the handlebars, and two red ones on the back of the seatpost. Two on each pedal. I should reinstall the two that came on the spokes.
Lighting: headlight on the handlebars that I run flashing during the day and solid to see with at night. I'm getting ready to upgrade my headlight and use the one I have now for flashing only. A red one that I run flashing on the back of my seatpost. On my helmet, two flashlights mounted side-by-side on top; these I run at low power as spot lights to shine where I'm looking, and being side-by-side gives me a nice wide binocular region.
Clothing: a reflective vest that goes over my shirt or rain shell. (I bought one vest then found four over time along the highway, probably blown out of work trucks. I think I have enough now to make a reflective pack cover.) On each ankle, a wrap-around band.
When I decide on a rack, I'll put a reflector and a flashing red on the back and a solid wide-angle red on each side, and maybe some reflective strips to. I can't bring myself to put adhesive strips on the frame.
I think tires with a reflective stripe are a great idea, but I can't bring myself to do that yet either. Vanity/aesthetics. But if I were commuting instead of riding for health and fitness then I definitely would.
I hope that helps.