What you wear to an audition should be planned. Don't just show up in whatever you happen to be wearing that day. You want to look professional. You want to wear something flattering. You want to be remembered for your performance, not the hot mess you're wearing. This is the performer's equivalent of a job interview, don't dress like the trashy contestant on a reality show.
That sounds so common sense, doesn't it? I can assure you that it's not. I can specifically remember an audition last year when dressing appropriately was the exception, not the rule. I sat there as woman after woman came in at their appointed time, and for the vast majority of them, my first thought was, "What is she wearing?!"
In my audition technique classes of yore, I was trained to wear a dress or skirt and character heels. I'm not so rigid to expect that, and in my experience, other casting directors don't expect that either. I still see lots of dresses, but I also see jeans, khakis, capris, etc. So while you have some freedom in choosing what style ensemble you will wear, keep in mind some guidelines...
BRAS
Wear one. Don't let the straps show.
TRENDS
Unless you're auditioning for an extremely trendy, modern show, steer away from this season's hottest trends. Often these trends only look good on stick-figure juniors models. One specific trend within the past year or two is the casual high-waisted tank dress. For some reason, these are very popular with the women I've seen recently. This style makes average or curvy women appear to have no waist and is nearly always too short. Here are a few examples of what I mean:
AMOUNT OF SKIN
Be a little conservative with the amount of skin you are showing. Don't make your audition panel spend the entire audition trying NOT to see something. I still remember one young woman from nearly a year-and-a-half ago. She had a large chest and we could see nearly all of it spilling out of her top. It was distracting. I had to force myself to look at her face (and I'm a woman). If you are unsure if your outfit is too revealing, change into something else.
WHAT TO WEAR
Now I am not a fashion guru. My sources of fashion education are Project Runway and some old episodes of What Not to Wear (they love a trouser jean and a good shoe!). And whether you are a fashionista or not, you should wear something that fits well and looks professional. You want clothes that are somewhat form fitting but not clingy. I'm partial to classic silhouettes like a shirt-waist dress. Maybe you prefer trouser jeans and a cute sweater. Find what flatters your shape.
And one final thought:
If the producer wrote down "Real Housewives of New Jersey" on your audition form, you're doing it wrong. (This really happened.)
