Educate yourself if this is a field of interest.  Some oils can be applied to the skin with a carrier oil (coconut or olive oil) for use on the skin.   Some essential oils can be used in a diffuser to fill the room with soothing or energizing scents, some oils even have antibacterial and antiviral properties.  

Pure Essential oils can be expensive, (but you are worth it, right?) or if you need to stick to your budget, some are more affordable having 90-95% purity.   You only need a few drops to experience benefits.  Again essential oils are used for different intentions and purposes.  You can use some on the skin with a carrier oil, some you can ingest diluted, others are placed in diffusers.  There are scientific papers written on health benefits of essential oils, especially on Peppermint and Lavender.   Please use with caution and read instructions before use.  (6)  Do your homework.

ENERGIZING OILS:  rosemary, clary sage, lemongrass, eucalyptus, peppermint (great for migraines) Tea tree, cypress, pine, lemon, basil, grapefruit, ginger are a few examples.

CALMING OILS:  Lavender, geranium, mandarin, bergamot, Patchouli, Sandalwood, and Melissa to name a few.  Get educated on how to use these oils, they are beneficial and potent!