Essences can be made with any natural item.  Most common are the flower essences, but gems, crystals & symbols can also be used, as I do in the Archangel range.  The aim is to transfer the energetic properties of the flower, gem or symbol into the water, which is then preserved with brandy or vinegar, and diluted to stock level ready for use.  It sounds simple, but as with any product of this type, there is much more in the detail.  

The process involves placing a flower into container of spring water, & leaving it to stand for a few hours.  Some people prefer to stand the water next to the flower, rather than cutting it to put in the water.  This method is obviously important where a plant's sap is poisonous.   Some crystals can also be toxic, & in this case, they are either placed next to the water or suspended over it.  When using symbols, I place them underneath the glass of water.

Other factors influence the strength & properties of the product, such as where the essence is made, the time of day/night, and which beings are called on to add energies to the mixture.  This is where each manufacturer's products become unique:  the maker's intentions & spiritual connections make a big difference.

Flower essences are usually most effective when taken little & often over a period of time.  In many cases, my essences are strong, & for each of these I have included a reminder in the detailed text:  take sparingly.  In most other cases, the normal starting dosage is 3 drops taken 3 times a day over at least a week.  if you are working with more deep-seated problems, take the essence 4 times a day, for a longer period - it could be as much as 3 months.  If in any doubt, tune in & meditate:  ask your guide, Higher Self or body elemental, & act accordingly.