Buying a waist trainer that is meant for your body type and for your comfort level is very important to ensure no body bruising and the best results. A waist trainer should be tight enough where it performs its function and pushes you waist in, but it should also not be too tight where it restricts your ability to breath and possibility posses bruising on your waist and stomach. First thing to do is to begin by measuring the size of your waist, which can be done by measuring the slimmest part of your stomach with a measuring tape. Your stomach should remain relaxed as you measure, no sucking it in. Depending on your goals, the waist trainer shouldn’t be more than 5 inches smaller than your waist size you measured. Another factor that is important in choosing the right waist trainer for you is picking high quality products with high quality materials. Waist trainers that are made out of plastic "steel" bones are often much more affordable, but they also often times lack in quality. The plastic material doesn’t provide the necessary support that is needed for proper waist training. A more expensive yet high quality alternative would be a trainer made out of steel boning, as these are much more durable and will provide the necessary support for waist training. There are two types of steel bones that are used in both waist trainers and corsets, those are flat and spiral and both serve their purpose. An easy way to check if your waist trainer is using actual steel or plastic is by using a durable magnet against the trainer. Waist trainers made from high quality material is important because it ensures that the product can be used for many times and for a long time without the trainer becoming loose or shifting; high quality also ensures that you will see the best results in perhaps a shorter amount of time. Happy training!