In celebration of daylight savings, I have done absolutely nothing to increase the visibility of my bike.
Because I already count on being visible 365 days a year. My bike is my primary transportation, and I can't be bothered with transportation that I can only use during the day. November, January, July, I ride in the dark and need to be seen.
I personally don't go in much for reflective clothing. I am a firm believer in reflective tire sidewalls however. Nothing transmits "bicycle" faster to the brainstem than two circles of light. I do have a retroreflective sash that I wear if it's raining, I'm wearing head to toe black, or it's Friday or Saturday night and I want just a little extra edge. I bought it at a running store, and like it because it's easy to stuff in my bag for an instant transformation into an ordinary person. It's also easy to shed if I'm trying to de-layer at a stop sign.
For maximum effectiveness, your lights need to actually be, you know, visible. Lights clipped to the top of your backpack so that they're pointing at the moon when you're bent over the handlebars, or on your seatpost hidden by the tail of your coat or the stuff on your rack aren't actually doing anyone any good, except possibly battery manufacturers. It's not a bad idea to have someone else either ride your bike while you follow them, or have them follow you when you're riding every so often to make sure everything is as visible as you think it is.
I like a combo of fixed and flashing lights. Flashing lights are eye catching, but can be harder to track when someone is trying to figure out how fast you're going (like before they pull out in front of you). A lot of people have rear blinkies because they're worried about being seen by cars from behind, but neglect front lights. Front lights not only help you see obstacles in front of you but they keep cars from turning in front of you, and help pedestrians and other bikers know you're approaching.
If you're a regular reader of this blog, you too probably have a lighting strategy in place, whether it gets dark at 4pm or 9pm. What's your favorite light, and why?