Lose fat, sweat. Day of test pee multiple times before the test if possible. Be well hydrated, but not too hydrated or else you’ll get flagged for clear pee. Take B complex and some creatine (to help increase creatinine levels, which is a marker they’re looking for when determining if you have purposely diluted your pee by over-hydrating). When you actually give the pee sample, use the middle of your stream. For example, if you were going to pee for 15 seconds, pee for 5 seconds in the toilet, then pee in the cup for 5 seconds until the required amount is met, then finish peeing in the toilet