Grocery store flavoring is low grade, don't use those.
There Are several high grade flavor manufacturers like capella, FA, TFA and a few more that are mentioned here in the forum.
Even those flavor manufacturers aim mainly at the food industry and not vaping, so some of their products are not suited for vaping purposes.
Oil based are not to be used.
Btw you referred to artificial flavorings, but in fact most of the flavorings, even the high end ones are artificial or a combination of natural and artificial.
This is a result of not gaining the desired flavor out of a natural extract, not being able to extract a product into the desired concentration or not being cost effective.
In addition some of the flavors that people have gotten used to taste wise, through the food industry, have nothing to do with the actual taste of the real product, like: coffee, banana, grape, honey.