This is a practical exercise in intention. When you write these checks, you are aligning your intention with the universe, signaling that you are ready and willing to receive. Doing this every month simply re-affirms that intention.
You don't need to believe the check will work, however you will be amazed at the results when you see increased abundance in some area of your life. It is not always financial but it will be in an area that you need.
If you don't have a checking account don't worry, you can draw a check on a piece of paper and fill it out in the same manner, the results will be the same. (Or feel free to print this article and use the check image.)
Do not put a dollar amount on the check and do not put a date. Place the check in a safe place and forget about it. The Universe will take it from there.