How do you use the menthol crystals? I have been thinking about trying them...
I have a small pestle and mortar, grind the crystals into a fine powder, mix with VG, nuc for
just a few seconds (don't overdue the nuc and don't leave it unattended or boil) then mix with your recipe as a flavor. You can also place in a bowl of hot water to warm the juice if you don't want to nuc it.
It takes some experimenting - a little mint or pepermint added to mix and/or a little malto deepens the flavor. I have also started mixing in a little clove which goes quite will with menthol. If you try clove be sure you're getting clear clove, not the real dark stuff - I've heard it will kill your attys quickly. Probably too much oil. It's also very strong (like menthol) so experiment on small batchs.
I usually create all of my mixtures seperately to the mg rating I'm using, then add or mix small quantities. That way I can experiment by mixing ratios of flavors together without cutting the mgs of the ejuice. I even mix individual cartriges that way. I pull the BFM, drip in the quantities I'm trying, shake it up and replace the foam. I haven't mixed a whole one or two mgs just as an experiment and I can get a pretty good idea of what it tastes like.