Originally Posted by
HillRider
For a front wheel flat (rare) I'll stand the bike upright on the fork dropouts after I remove the wheel. For a rear flat, I remove the wheel with the bike upright and lay it down on the non-drive side while I change the tube and then hold it upright while reinstalling the rear wheel. I don't want to turn the bike upside down and scuff up the saddle and brifters.
+1....A common thing in a bike shop is for someone to come in with their bike, and before saying a word flip the bike upside down in the middle of the floor and beckon for someone to come over and take a look at whatever the problem is. Depending on the specific situation we typically go over and politely talk to the person about what they need and then take control of the situation by righting the bike and wheeling it away to the repair area.