if you are getting tested for work drink massive amouts of water.try and piss like 5 times before you go.then hold your pissd and pee out the fresh water.
the proteins they are looking for will be diluted.

if you are testing for parents just say you refuse.
doctors can not order you to take a drug test without your consent.
i work in a clinic and the moms are always coming in for drug tests for there kids and if the kids say nope the docs cant do shit.
drives the moms crazy but the kids love it