What mg level do you vape? I'd suggest more PG, but if you like the thick clouds but not the PG irritation, I guess that's not really an option -- there's this other stuff called flash, supposedly makes the TH better, but I'm not really sure it's all that effective. I've also heard that diluting just slightly with high-proof grain alcohol is supposed to make it harsher, providing more TH.
Andria