The only RIGHT WAY to do it, is to remove all restrictions and penalties for cultivation, possession, and use... but require a business license for selling. The currency is theirs, they can decide what is or isn't acceptable usage of currency.
Just like anything else sold for human consumption, there should be some kind of qualification process, and it SHOULD NOT be based on who can afford the license, but rather, who can prove they aren't selling something tainted or harmful. You can tax Sales and Purchases, but if i want to grow plants for myself and for bartering Without Money Involved, no one should intervene.
They also have to remove restrictions on whether i'm allowed to have THC metabolites in my body. There needs to be a new test developed to determine whether someone IS ACTUALLY HIGH RIGHT NOW, instead of ostracizing everyone who was high within the last month or few (sometimes longer).
I should be allowed to grow, possess, use, and share, completely freely.
If i want to "do business," then that is acceptable to subject to regulation, just like any other business or selling of goods. Why? Because i didn't invent the dollar, and those who "own the dollar," are the rightful authority on what i'm allowed to do with it, since it isn't actually mine. Whether you define the proper owner "the government" or "the federal reserve," they only allow us to use dollars, so that they can profit from controlling the currency. If no one was able to profit from controlling currency (and subsequently what it is allowed to be exchanged for), there would be no federal reserve, and it would be impossible to make "buying and selling" (with dollars) illegal.