A few tips that I learned a long time ago when changing a flat: #1 - Carry a small container of baby powder. After slightly inflating the tube to give it form apply the baby powder to the entire tube. This will greatly decrease the possibility of the dreaded 'snake-bite flat' that occurs when the tube has a slight twist after inflation. It also will help to keep the tube from sticking the the tire. #2 - Inflate the tire to about 50psi, check to make sure that the tire is seated evenly around the rim, then fully deflate the tube. This will also help to prevent a 'snake-bite flat' by greatly decreasing the possibility of a slight twist. #3 - Do not screw the bolt that comes with the tube onto the valve stem. This might prevent the tire from fully seating itself correctly around the tube.