The best way to smoke some 20x is to go full out. Pack a big bowl, bigger than you need, then take a huge hit. Hold for a long fucking time, like 30 seconds, exhale, then immediately take another hit. Hold for 30 seconds, exhale, and if you're still in this world, take a third hit and hold. Make sure you have someone around you because by now you should be so far out of your body you'll forget to exhale or breathe.
Expect some crazy shit.
