How do I stop this? I’m taking a big breath of air and holding my breath, and then lightly sniffing my pinch, but I’m still getting snuff in my throat. I’m still pretty bad at snuffing but I love it so it kind of sucks 
Search is your friend. Try closing your throat the moment you sniff (i.e, as if you were submersing your head in water).
I don’t think I close my throat when I submerge my head in water. I’ve tried doing what you said and I just end up making that noise from The Grudge. Maybe I’ll get better at it.
Well, another way of explaining it is to breath deep through your nose. Hold it. That holding it in is the throat closing I’m talking about. In effect, you do that right away to prevent doing a too deep a sniff. With time, most seem to forego this method after learning better sniffing control.
That sounds like it should work, I’ll give it a shot. Thanks.