I tried using essences when I brewed my first batch of neutral and none of them were any good in my eyes (except Sam Willards Smooth Rum, it's very close to Bundy Red, if you like that sort of thing), so I went to using molasses for my rums and have only just started sampling the results after ageing on oak.
BUT...
I was given my still and along with it, a whole bunch of rum and bourbon essence.. 2 flavours and about 300mL of each. Which would probably do about 12-15L of 'rum/bourbon'. Now they don't taste much good just mixed with neutral - but I'm thinking of mixing them with other ingredients to see if they can get any better.
Any tips? I'm thinking essence, oak, vanilla, clove for rum and just essence and maybe charred oak for bourbon?