Before you get to this stage, ensure you have viewed our size chart. If your gi is a perfect fit upon purchase only ever wash your gi in cold water and line hang. It is important to shrink in stages, the first step is to hot/warm wash your gi, then line hang and test. The next step is to cold wash your gi and dry in an electric dryer, test again. If you still need to get a bit of shrinkage you can hot wash and then dry in a dryer. You may need to dry in an industrial dryer if the above doesn't work.