If you have noticed water standing on your court for more than an hour after rain it is a good idea to fill those areas to minimize ponding. This is important because, as you may have noticed, standing water can degrade the tennis court paint and cause mildew to flourish. To properly flood the tennis court you should simulate rain as closely as possible. This is done by holding the end of the upward, placing your thumb over the opening, and creating as spray that cascade down onto the surface. Spraying the water horizontally can push water out of the low areas, giving you an inaccurate assessment of the patching required. You should continue flooding an area until you see the water beginning to run off. Another, easier, method is to let the rain do the work for you.
Whether checking the court after hosing it down by hand or after a good rain, you should wait one hour after flooding to inspect and mark the standing water spots. The U.S.T.A. classifies a puddle standing on the court surface, one hour after flooding, which is deeper that 1/8", as an area that should be patched. A simple inspection method is to throw a nickel into the puddle. If the water covers the top of the nickel, the spot should be patched.
When you find a puddle that covers a nickel, use a yellow or white crayon to mark around the outer edge of the standing water. Some court surfacing experts will use some kind of shorthand in the middle of the patch to give them a little more information as they are patching. This may be in the form of 1/2, 1/4, 1/8 to designate the depth of a particular patch or something as simple as a D for deep or an S for shallow. Wait for the standing water to dry completely before starting the patching. You may want to hurry the process along with and blower and/or a squeegee.