Dress the part. If the pitch is for sports equipment, pick out your most stylish workout clothes. If you're auditioning to pitch products for stay-at-homes, looks as homely and matronly as you can.
Research the product you'll be pitching ahead of time. The most important thing in commercial auditions is to be positive and enthusiastic about the product you're selling.
Read over the script right before the audition, and memorize as much of it as you can. There will likely be cue cards to guide you during the audition, but it is best to deliver as many lines as you can while looking into the camera rather than looking off at the cue cards. It's OK if you make minor flubs during the audition, but don't ad-lib.
Ask to read over a storyboard of the commercial if there's one available. This will give you a sense of how the commercial should go. Take note of the action and how the product plays into the commercial, as well as the small details such as posture.
Once the camera is on, look straight into the lens and state your name. Take a breath and with a warm and friendly approach (unless the script calls for something contrary to this), look into the camera and deliver your first line.
Imagine that you are talking to a friend in the comfort of your own living room while auditioning. A successful commercial audition requires you to be easy, comfortable and naturally enthusiastic about the product. Pretend that you are simply sharing a fun story about an item you are jazzed about.
"Punch" the name of the product. This means that when the product name comes up, give it a slight emphasis. It should be barely noticeable but enough to make the product name stand out.
Be aware of the pace of your reading. Many people tend to rush their lines when nervous.
Take natural pauses when called for. This is most effective right before announcing the product name or before delivering a significant piece of information to the viewer.
If you are given a product to hold during the audition, make sure it is seen on camera. The way to do this is to hold it near your face. It may feel unnatural but because the camera adds space between objects, it will look normal. Also, don't forget to refer to the product as you speak about it. This is accomplished by simply giving an occasional nod toward the product.
On your last line, continue to look right into the camera until someone calls it a wrap.