It's not uncommon for new shoes to rub your feet the wrong way and cause a few blisters. Real Simple suggests a bit of gel deodorant on key friction locations can reduce the stress.
The gel acts as a moderate lubricant, which can obviate the need to buy dedicated blister blockers. It should be noted that this method probably isn't for runners, as deodorant can prevent sweating, which is essential to staying cool. If you're trying to make new shoes a bit more comfortable until they're worn in, however, that gel deodorant you have lying around is an excellent substitute.