Punctures and pinch flats happen less often with proper inflation. The thinner the tire the higher the pressure, and the more often you should check inflation levels. The range printed on the sidewall is a good place to start.
Higher volume tires not only smooth out the ride, but go a long way towards preventing flats. A large enough tire can roll over anything, a 28-32 mm tire can roll over most anything in the city.
Lightning can strike twice. The small slice from your last flat may be just big enough for another piece of debris to squeeze into—try to close it with superglue. Worn tread is more prone to flats, exposed threads is cause for immediate replacement.
Flat Proof Tires Or Liners
The current generation of flat-resistant tires are exceptionally good at preventing common punctures, and well worth the investment. Tire liners are a reasonable, affordable substitute. A heavy, inflated tire is far better than a lightweight, flat one.
Get out of the saddle over the rough stuff, and avoid debris prone areas when possible. Bridge sidewalks and unofficial trails, derelict playgrounds and parking lots all make great shortcuts, but accumulate broken glass. Ride with caution.
Spending the extra time to be absolutely sure you found the cause of a puncture can save you from repeated flats. Make sure you remove any debris from the tire—look closely on both the inside and outside of the tire, it may be buried in the tread.
There is no set limit on how many patches are too many. Patch on patch on patch, I’ve had tubes with a dozen patches holding it together before I finally tore it or broke the valve.
Don’t Pinch The Tube
When replacing the tube be mindful to not pinch the tube between the tire and rim. It’s easy to do with skinny tires or tire/rim combinations that are unusually tight, and can lead to an unexpected and unpatchable blowout.
Careful With That Valve, Eugene
Especially with presta valve stems, be careful when removing a pump head or using a hand pump. Be gentle and minimize sideways movement. It doesn’t take much to tear a presta valve from the tube, or to break the delicate brass valve core.