I actually don't mind the Queens essences (sorry Com), especially when they're either already in your pantry, or readily accessible at the local supermarket at a around $1.05/bottle.
Here's a couple of obvious ones...
Boosting Weak Coffee
To fix the blandness of Dekang Coffee - which seems more like a latte in recent batches - add a little (3-5%) Queens Coffee Essence.That latte will fast become an expresso.
Flavours too harsh
If you have a menthol, mint or even tobacco flavour that's too harsh, add a little vanilla
ejuice (or a few drops of Queens Imitation Vanilla Essence) to it. It infuses body and takes the edge off those sharper flavours.
Vanilla Mixes
Don't buy Queens Vanilla Essence - use the Queens Imitation Vanilla Essence. There's no issues with the sugar on your atomisers with the imitation version, and the taste difference is negligible (yes I did try).