If you are on the waiting list, the first thing is to congratulate yourself, because you are still in the running. While you were placed on the waiting list, other candidates were outrightly rejected. Currently, the decision could go either way and you might feel that there is nothing you can do. This is true in some situations but not in all situations. If you have been placed on the waiting list, this is a good time to contact the potential supervisor you chose (if applicable) and inform them that you have been placed on the waiting list. It is the time to email them and show them why they should take a chance on you. You can do this by reiterating your strengths and how you intend to contribute to the university. You can also use this opportunity to mention any improvement to your qualifications since you last applied. If you have applied to other schools, you can contact the school that has placed you on the waiting list to inform them that you need a decision between them and the other schools soon so you can make a choice. This might speed up the decision making process on your file, but it does not guarantee that you will be accepted. When on the waiting list, you need to apply wisdom to ensure that you take the right decisions.