Dress code

The one great thing about hairdressing which I love, is that you are allowed to wear a huge variety of clothing; as long as it is either white or black. As long as it is appropriate though. You can't go walking around at work with booty shorts and a top that barely covers anything. You want to make a good impression to your clients, but you also want to be creative, since hairdressing is all about being creative. With you hair, it's up to you. You can have whatever hairstyle you want. People are going to expect you to have a Lady Gaga style hairdo, or just a plain sleek ponytail.
You also want to me bubbly and talkative. Unless the client isn't in the mood to talk, you should still be able to keep up a steady conversation. You don't want to seem moody, the client will think you will take out all your anger on their hair, and they came in to get a good hair cut, not a disaster.
Even when you aren't on the job, and are out doing errands or what-not, you still want to look appropriate.