Inform yourself

https://psychonautwiki.org/
https://www.erowid.org/
https://tripsit.me/tripsit-releases-v3-0-of-its-drug-combination-chart/

Get your chemicals

http://syntharise.com/
http://science.bio/
https://botany.bio/
http://chems.ca/
http://rechem.ca/
http://chemlogix.ca/
http://realchems.net/
https://indolesinternational.com/

See also: Become a trusted vendor

Test your chemicals

https://testkitplus.com/product-category/test-kits/drug-identification-test-kits
https://getyourdrugstested.com/