If it were me, I'd stick with flavorings that are generally used for vaping. Some you might be able to get in person if you have a restaurant supply or baking store near you (but caution, not all flavors are best used in DIY). I really think your best bet is to order from a DIY Wholesale vendor that is specifically for e-cigs, in my opinion (though at times it doesn't seem safer) you are better off using what is tried and true in the e-cig market so far. Yes, we don't have a LOT of data, but at least they've been being used for some time, mostly without incident. If you start choosing other things, you really are in wild wild west territory, no one knows much about them.
If you must do this (I really, really wouldn't) make sure you aren't vaping things with a lot of oils or alcohols, and I don't think there's a really easy way to figure that out....
Best of luck,
Anna
