If you have a vaporizer that works with liquids, or just want to know how to make a glycerine tincture then check out this excellent video which explains how to properly infuse glycerine with cannabis.
Note this comment from the original poster of the video:
“Please note i made a silly error when creating the video, the ratio is 7 parts VG to 3 parts VG. So for my example of 5g of herb there would be 28ml of VG and 12ml of PG. I hope this clears everything up, sorry for any confusion caused! If you still are unsure simply leave a comment and I will try to get the them all. Thanks for watching!”
Instructions come at the beginning of the video followed by an actual demonstration.