--Just start off with a small amount and work your way up to a comfortable level for yourself. Everybody has a different tolerance depending on many factors.

--Once the herb turns a chocolate looking brown you can save it for cooking.

I got my iolite about a month ago.
It has a fixed temperature so you can not vary the temp.

A couple of things I have learned:
--It uses gas quickly so I now fill it after every use
--After I fill it I wait about 15 minutes or so before I try to start it up.
--When you turn it on you will hear the gas hissing--I let it hiss for almost 15 seconds before I hit the igniter. If it does not start--you can see a yellow light to confirm it is heating up--just try again.
--I push the igniter very slowly and then hold it it. This always works for me.
--After you turn it off it will continue to hiss and produce vapor as it cools down so keep that in mind as you will lose valuable vapor.
--I take maybe 3 or 4 inhales and then shut it off since I will continuing to take in vapor.
Again,you need to customize the amount, # of hits etc etc to suit your own tastes and needs.