First of all, i do not promote illegal or legal substances, this article it's meant to be for harm reduction purposes.
Drugs are everywhere, the chance of you knowing someone who does or even you doing it are pretty high. That's why is so importante to be aware of the right setting to do it safely, as your life or someone else life is on the line. So here it goes some tips you can follow.
First tip!
Always test your substances!
Most of the drugs you will buy you do not know for sure if what you are consuming it's the real deal or some fake mimic potential dangerous research chemiquals that dealers use to make more proffit. So to be sure of what you are taken you sould buy test kit. Your life is more important that spending this a extra few bucks!! You can find test kits here http://testkitplus.com/
Second tip!
You sould absolutely do it a research of the specif drug you will take. Don't take for guaranteed the informacion that your friends or dealers says, ALWAYS do a research.
In my opinion this sources are very good, this one will give you more informacion on various drugs https://www.youtube.com/user/TheDrugClassroom and this one will give you the informacion and the stories of Adam or better know as "PsychedSubstance" https://www.youtube.com/channel/UCn8V3KNSgDr1Dai77_y8JrQ .
But there is a lot of a good forum too, always check the informacion if is correct.
Well that's it, i can not go longer because the settings of one drug safe is differente to another.
Stay safe and i hope this informacion help you.