I can't give any advice; the reason I don't get flats is that there are no road hazards around here. I guess my advice would be to move to an area where the drunks throw cans out their windows instead of bottles, and cars are not parked on the side of roads and have their windows smashed.

I can put the thinnest, crappiest tires I want on my bike and ride 1000 miles without a flat. I just mounted Marathons for endurance, not for flat resistance. I figure $26 for a tire expected to last 8000+ miles is a better investment than $15 for a 2500 mile tire.