Drink a gallon of water immediately upon finding out you have to piss. It's gonna suck but drink it in 5 to 10 minutes. Wait to pee until you feel like you're gonna explode. Try to pee twice before you pee in the cup. Only use your mid stream urine in the cup. This will make ur urine water until your kidneys flush the water out. To compensate up your creatinine levels. Take the stuff listed below.
Creatinine is a normal byproduct of muscle metabolism that is present in urine at specific levels. Creatinine levels are one of several "benchmarks," including pH, color, and specific gravity, assayed by urinalysis examiners to weed out diluted samples. In response, would-be drug test "thwarters" engage in several tried-and-true methods – including consuming Vitamin B, riboflavin, and even creatine supplements – to maintain these levels within the ranges acceptable to drug testing labs.