Essential oils smell delicious, but I have a reason for using them on you, beyond this....
Maybe today you're a bit keyed-up -- perhaps didn't sleep last night? I will finish your treatment with Lavender Oil applied gently to the soles of your feet for easier absorption and effective meridian coverage. Or maybe you've been plagued with headaches? It's peppermint oil for you, applied to temples as well as feet.
Essential oils should be treated as you would treat herbs and vitamins...your body may need one but not another -- and you can absolutely get too much of them.
Note: If you prefer I not use any oil or lotion, that's fine...as a matter of fact, it's forbidden to use any such preparation during the NYS practical reflexology exam.