If you have sensitive breasts, you may wish to abstain from caffeine (coffee, tea, soft drinks, chocolate) for 3-5 days prior to your exam. Caffeine may cause your breasts to be tenderer.
Dress preferably in a 2 piece outfit, such as a skirt or slacks and a top, since you will only need to remove your clothes from the waist up.
Do not use body powder, deodorant, or cream on your breast or underarm area on the day of the exam. These products may leave a residue that can produce artifacts.