Avoid Flat Bike Tires
Flats are an unavoidable fact of life, but they can be reduced by:
Keep your air pressure high to avoid pinch flats--punctures caused by the rim crushing a hole in the tube when you hit a bump. A hole on the inside of the tube, or a "snake bite"--2 holes on the inside of the tube, prove a pinch flat. The maximum psi should be stamped on the outside of your tire. Check tire pressure weekly and keep it at the maximum.
Don't slam into bumps. Some people like to lift their front wheel over a curb and bang the rear wheel right in to it. This causes flats, damages the rim, and loosens the rear axle, leading to a broken axle.
Buy tires that are pinch flat resistant--that have thicker walls.
Use bigger tires--tires that hold more air, for more cushion against pinch flats.
Ride on clean surfaces. Don't ride across grass that is likely to have stickers. Look out for glass on streets.
Use a tube sealant, like Slime. Sealant can be added to Schrader valve tubes. Slime sells tubes with the sealant already in them. Sealant is a favorite in desert areas, where there's tons of thorns. Sealant won't work against cuts, large punctures, and most pinch flats. The downside is that sealant sloshes around in your tube, and you can feel the weight shifting as you ride.
Buy thorn resistant tubes--tubes with very thick walls. The down side is that they are very heavy.
Use a tire liner, like Mr. Tuffey. Tire liners are a thin strip of a tough material that goes between your tube and the inside of the tire. They are effective against punctures, but not against pinch flats. The downside is that the edge of the tire liner can wear a friction hole in the tube, but this can be reduced by keeping high air pressure in the tire.
Buy tires that are puncture resistant. Some nicer tires have a layer of kevlar and are not any heavier than other tires, but they are more expensive.
Replace tubes instead of patching them. Patches fail, especially glueless patches.
Make sure your rim strip is doing its job. The rim strip goes around the outside of the rim and protects the tube from the spoke nipple heads or spoke holes. The rim strip has to cover anything that could cause a puncture. New wheels sometime come with lousy rim strips. It is best to use a good quality rim tape, like Velox. A hole on the inside of a tube indicates either a pinch flat or a rim strip problem.
Inspect the rim for barbs on the inside.
When installing a new tube, be careful not to pinch a hole in it--it's very easy to do.