If you're looking for an essential oil to help you relax and fall asleep Lavender is one of the best. Use in a diffuser at night to help you unwind, relax and drift off to sleep. There are also many aromatherapy blends containing Lavender and complimentary essential oils like Sweet Marjoram.
If you don't have a diffuser place a drop or two on a cotton ball and place in under or inside your pillowcase. A terra cotta aromatherapy stone is another excellent choice in place of a diffuser.
You can also create a pillow mist by mixing a few drops of essential oil with water in a spray bottle. Spritz your pillow and bedding before bedtime for a soothing and relaxing scent.