I am not an expert on essential oils. I am not a certified aromatherapist. But I do study and use the oils. I use them for their scents and skin care applications. I do not use them medicinally or give advice on their medicinal uses.
However, I do know more about the oils than the average person. In 2004 I took an intro to aromatherapy course. I have read many aromatherapy books and over the past few years have used many different oils.

My posts about essential oils will be for the average person. Just a little of what I’ve read and learned to help the average person be more comfortable using essential oils.
First, use common sense. When trying essential oils, always look up the warnings for the oil you want to try. Many do not have any but some do. If you are pregnant or have a medical condition, you need to know the precautions. For example, you should not use Peppermint when you are pregnant. When you see foot creams/lotions for your aching feet that contain Peppermint Stay Away! Peppermint is an Emmenagogue which means that it stimulates menstruation.
For that matter, if you are pregnant, always ask your doctor before using any essential oils. And you should stay away from fragrance oils too! Who knows what chemicals they can contain!
Next, if you don’t like the scent of an oil, don’t use it. Just like you would not eat something that does not sit well with you.
And finally, if you are allergic to something, don’t try the oil that is derived from it or something similar to it. Like if you are allergic to grapefruit, don’t use grapefruit essential oil! Duh, you say. Well you would not believe the number of people who cannot grasp the fact that grapefruit essential oil comes from a grapefruit! We are so conditioned to using fake fragrances.