Shopping in a hurry
One mistake that many men make is that they rush into the purchase. It is not likely that the first pair that you try will be the best one for you. Most people will agree that you will go through at least 6 pairs before you find the perfect one. This means that you should allow yourself at least 45 minutes to shop (women this is not for you!). When choosing jeans, make sure that you choose the right fit from the waist to the knees. Snug fitting jeans are flattering but you should also think about your body type.
Ignoring the hem
It is important to think about the hem when shopping for jeans for men. Think about the shoes you will wear with the new jeans and remember that the hem needs to be long enough to cover the top of your shoes. Pants that are too short look ridiculous and you are better off going too long instead of too short. Remember that length can always be adjusted and if you find the perfect pair of jeans but they happen to be too long, remember that a tailor can adjust the hem.
Failing to test the fit
When testing the fit, you cannot simply stand straight before the mirror and hope to get an accurate picture. You need to bend and squat and try to get a feel for the trousers and the coverage. You have to make sure that there are no gaps when you haunch down. Remember that you will wear the jeans while up and about and not simply standing still. It helps to have someone with you while you shop but if you are alone you should not be too shy to ask for opinions from a sales assistant or fellow shopper ( it is okay, women do it all the time!)