I'm going against the norm...I wear my tights under my chamois bibs. I like the thermal next to my skin, and if it's cold enough for tights, layering isn't an issue. That said, I don't wear tights unless it's under 35. Until then I wear knickers, smartwool long socks, booties, long fingered gloves, wool base layer, ss jersey, arm warmers, thermal jacket/vest. And if I'm going to be taped and it's sub 30, I throw in hot pink fishnets http://vimeo.com/12587416
Climate and cold tolerance is so different. My winter layering has changed every year. But I did learn that less is more. If you're warm starting out, that's a bad thing. I used to come home freezing, it was because I was too warm starting out.
"The bicycle is just as good company as most husbands and, when it gets old and shabby, a woman can dispose of it and get a new one without shocking the entire community." -- Ann Strong, Minneapolis Tribune, 1895