I'd be cautious about adding significant levels of essential oils, especially directly to the buds. You don't know how your lungs will react to their vapor, and some people are quite sensitive to certain oils.
Safer bets are to take the dried bud and jar it up with a small piece of dried citrus peel, star anise, a cinnamon stick (be real careful with cinnamon as it may be irritating), etc. but not adding a liquid oil to the bud itself. I have had DELIGHTFUL results putting buds in a jar with a couple saffron threads for a rich, earthy flavor.