I stopped riding so much. My number of flats went down dramatically!
I've had reasonably good luck with the Conti GP4000 tires. The Michelin Carbons were more flat resistant, but could be downright scary on damp, cold days. The Contis definitely grip better. Once I get 2 or more flats in a week, I'll check the tire carefully. If it's worn down past the wear indicators, or has any particularly nasty cuts, then it gets binned. I still get some flat tires, but I'll get about 2,000 miles out of the rear tire, and twice that out of the front, as long as a tire doesn't get cut up too badly.
I carry 2 spare tubes, 2 CO2 cartridges, a flat kit and a small pump that I hope I'll never have to use.
JB