A good stance is critical in every tennis serve. The form of your service being should determine your stance. Always remember that your feet should be about shoulder width apart.  It should be approximately 2 feet distant from the center mark, front foot a few inches from the baseline and knees should be a little bent. Having the correct stance ensures the most effective tennis serve.  The tennis serve is a complicated shot but it can be your most powerful weapon and a reliable one.  It helps you win more tennis match if you know the basics involved in tennis serve.