You don’t. This is why you see a Board-Certified Plastic Surgeon such as me who has a lot of experience in breast surgery. Having said that, a simple test that you can do at home to determine whether or not you may be a candidate for a breast lift is the pencil test. Place a pencil or pen beneath the crease of your breast. If it stays put, you have some degree of ptosis or droop that may need to be addressed with a breast lift.