Dressing rockabilly is part of living the rockabilly lifestyle. You love Elvis Presley, Johnny Cash, Brian Setzer, and Dick Dale. You are unique and stand out in a crowd. You are rockabilly.
Hit up the thrift stores. Your best source for rockabilly wear is a thrift store that stocks vintage clothing from the 1940's and 1950's. Research stores in your area and call around to make sure that the store you hit carries the styles you are looking for.
Scour the racks. Women will be looking at dresses and men will need to take a look at vintage bowling shirts.
Search out one of two styles of dresses. Either go for the tight fitting below the knee dress. This is sexy and hot, and takes a wonderfully wild women to pull it off. Sweetheart necklines are always a winner. The second dress you will be looking for has a full skirt. You can swing your little rockabilly legs in this dress and most women, regardless of their size, are able to fully rock this style.
Look for vintage bowling shirts and Vegas shirts. These shirts should have at least two colors. They can be worn buttoned, while you're holding a cocktail in one hand, or unbuttoned with a plain white t-shirt or wife-beater underneath, a great belt and a loose pair of jeans.
Find some shoes. Shoes are the next step in your journey. Look for classics such as Converse All-Stars for guys or sexy pin-up girl shoes for women.