When going out to do a photo shoot it is not very likely that there is going to be a makeup artist, or wardrobe person on site unless you are paying the big bucks! So what does that mean for you?
Well if you have a sense of style and color then it's not so bad. If you are working outside it is best to wear bright colors like blue, red or yellow. Sometimes your photographer will tell you what color to wear, for instance if he/she is going for a "high key" look they might ask you to wear white.
When doing a photo shoot in a studio there is a lot more control over what is in the background so it is important to know weather or not you get to chose what the background will be. Some portrait studios will have a variety of colorful and imaginative backdrops but others will only have a select few usually in black,white, browns and grays. You will need to find out what your options are before choosing appropriate clothing.
Accessories are best to kept to a minimum unless the theme of the shoot allows for lots of glitter. The reason you do not want to wear a lot of jewelery or over the top accessories is because it distracts from your face and will some time cause a reflection or shine from the flashes. Hats and sun glasses cause shadows which gives most people a sunken eye look, unless your photographer has a reflector to push light up into the shadow.
The most important thing to remember when deciding what to wear on your photo shoot is that your comfortable in the cloths. Ask yourself; Do I feel good about myself in these cloths? Are they appropriate for the season? Are they clean? If you can answer yes to these questions that you will be dressed up with some place to go!