There was a time flavored rolling papers were banned.  All this did was create a way for advocates to build a better mouse trap.  Basically everybody started "spraying" on the flavor and allowing it to cure.  The demand for Blueberry, Strawberry, Tutti Frutti, and Watermelon sky rocketed from 2008 to present day. 

Some people tried dried powders or wet powders such as "Cool-Ade ."  These were not designed for toking and the color also interferes with the smoke.  Powders do not work in general.

I am a tea leaf flavorist and have worked in the herb flavor market long before the magic puff come along.   

Now enter the vape market; e-cigarettes, DIY e-juice, e-liquid,  and we have a lot of people puffing up a storm.   

Basically flavoring your "stuff" comes down to needing a professional flavor you spray on [the people who make McD's cherry taste more cherry, and DQ's vanilla more vanilla] and how to apply that flavor.  Generally professional flavors rock the house and you only need 3% max of that to your "end product."

Oil Based or Water Based Flavor?  That is the Question

Vape people need water based so they can end the reading right here.  Water based is great because you can also make edible massage lotion with it.  Edible massage lotion is just vegetable glycerin and whatever water based flavor you want to stick in it.  For people not vaping, and tossing spice blends together, K2, JWH or weed blends...

Do you use heat lamps?

If you are using heat lamps you will want an oil based flavor.  Sprayed evenly with your concoction the oil based flavor will cure and with stand the high heats far better than a water based.

If you are not using any heat to cure, a water based flavor will be much better.   Spice makers use both-but one prefers oil based when using hot lamps and one prefers water based when using air to dry.