The first step in making your own synthetic urine is to get the ingredients. If you're trying to pass a test, you'll need to buy the right product. You'll want to look for a trustworthy brand that will give you full transparency on the ingredients and expiration date. You'll also want to try out a few different brands and formulas to ensure you get the best quality. If you're using your synthetic urine to pass a test, you may want to consider buying the powdered form. This way, you can make sure everything goes according to plan on the day of your test.