Todays essences are an extremely close match on the equivalent commercial spirits and liqueurs. All you need to do is add them to your filtered spirit or commercial vodka to recreate your favourite tipple. Instructions are on each pack or bottle and you should read these before using the essence. Some ranges of essences produce different quantities than others.
When making spirits you simply add the essence to the appropriate volume of filtered alcohol. When making liqueurs you need to mix liquid glucose, sugar, alcohol, water and the essence. In the case of cream liqueurs you need to add cream as well. First warm the liquid glucose and mix with any water. Using boiling water will help with the dissolving. Add the sugar to this and any alcohol. Mix well until dissolved then add the essence. In the case of cream liqueurs, the cream should be added last to the cool mixture. Using shelf stable cream will lengthen the life of the liqueur. Any cream liqueurs should be stored in the refrigerator and consumed while fresh.
Helpful Hints.
1. Some flavours need a few weeks to age. All liqueurs become "smoother" over time.
2. Liquid Glucose - can be added to slightly thicken liqueurs, without sweetening, and give a smoother mouth feel. A powdered version, Liqueur Thick, is also available for easy mixing. Dissolve, (perhaps in a little boiling water), before adding to your spirit base.
3. Top Shelf Mellow Oak Extract - can be used to add an oak flavour if required. Add 5-10mls per 5 litres. This is particularly appropriate for Whisky, Brandy, Bourbon and Dark Rum.
4. Distillers Caramel - This is a commercial caramel that is stable in spirits and can be used to darken any spirit if required.
5. Glycerine - Improves texture and mouth feel in liqueurs and spirits. Use about 5ml per litre.

nb: Adjust the essences to your own taste by increasing or decreasing the amount you add; or using some liquid glucose or even mixing essences to get the exact taste you require.