I use Lavender to help my sleep and rose oil to improve my skin.
As for the diffuser, I recommend Sztrokia Aroma Oil Diffuser.
I had two diffusers but they were too noisy to make me relax and fall asleep.
Sztrokia oil diffuser is the third one I bought on Amazon, its quiet running and fine mist output. I LIKE IT!
Hope it works! Thanks! https://www.amazon.com/dp/B01I9ISI12