When using essential oils, it is important to know and trust the source that you get them from.
There are different grades of oils - some are used for perfumery, some in the food industry, and only therapeutic grade oils are used in the legitimate aromatherapy industry.
As a guideline, when purchasing your oils, make sure the botanical name of the plant is on the bottle. For example, Lavender could have Lavandula angustifolia on the bottle. Ginger could have Zingiber officinale.
Sometimes the botanical names will be different, depending on the variety of plant used. For instance, there is more than one type of Sandalwood. One variety would be Santulum album, another would be Santulum spicatum.
So you need to know what you are looking for. Make sure the botanical name is on the bottle.
Another good guideline is to ensure the bottles of oils are not all the same price. Oils can range from under $10 for a 15ml bottle, right through to more than $150 for a 3ml bottle. It depends on the availability or scarcity of the plant or flower being used. There are many varying factors and they all come in to play to influence pricing.
There are cheap 'fragrant' oils available, but these can be petroleum based and have no therapeutic value at all and are definitely not used in aromatherapy. Some of them could actually be harmful to your health. These oils though, will not have botanical names on the bottle, and will generally be around the same price regardless of the scent, and the price will usually be only a few dollars.
The non therapeutic essential oils are quite easy to spot if you know what you are looking for.
Another interesting factor with essential oils, is that they are either top note, middle note or base note. The particular note an oil belongs to is relative to the molecules in the oil (mostly small, mostly large or a mixture of both) and how quickly or not the oil evaporates.
Top note oils are generally for wellbeing and uplifting. Citrus oils are top notes, and they are known for their cheery personalities and uplifting qualities. They are very helpful if you are feeling down or depressed.
Middle notes are for normalizing and balancing. Lavender and geranium bourbon fall in to this category. They will bring harmony to out of balanced emotions, helping you feel balanced and centered once again.
Base notes are calming, relaxing and sometimes sedative. Base notes include such oils as ylang ylang, frankincense and rosewood. They are usually stronger smelling, and you normally would only need a couple of drops if using them in a blend. They can sometimes be overpowering if too much is used.
When mixing a blend, it is a nice balance to have an oil from each note in the mix.
Aromatherapy is a wonderfully healing practice on all levels. It can work in conjunction with other modalities or on its own. But it is most important to have a trustworthy supplier for your essential oils so you know you are getting therapeutic value.
If you have a pre-existing condition it is also most important to consult your doctor or qualified aromatherapist for advice.