I'm sorry, been MIA and didn't know I had messages here. Have you had any e-cig tincture luck in the last year?! 
I have made tincture with bud, kief, and both combined. Haven't made any in a while, though... I am pretty much housebound, so my Vapor Genie does the trick. I only use tincture in my PV if I am away from home and desire discretion. Kief/hash/oil are the way to go for PV tinctures, though, as you can get more potency with less taste/smell... perfect for discreet vaping. 
I have made tincture with bud, kief, and both combined. Haven't made any in a while, though... I am pretty much housebound, so my Vapor Genie does the trick. I only use tincture in my PV if I am away from home and desire discretion. Kief/hash/oil are the way to go for PV tinctures, though, as you can get more potency with less taste/smell... perfect for discreet vaping.