It needn't be complicated. A few drops of essential oil in a warm place close to you will work wonders on your state of mind.
If you like you can buy an aromatherapy diffuser. Most of them would be something that was pleasing to the eye and had a place to put a small candle with a small bowl on top to put some water and a few drops of oil in.
Then just light up the candle and you are in business!
Try lots of different essential oils and mixes of them. But use the real thing! Artificial fragrance oils just aren't going to have the same effect. And with essential oils a little goes a long way.
Lots of places sell essential oils. I get mine from one of my local health food stores. But I know of stores just dedicated to aromatherapy. If there isn't a source for them close to you, well, everything is available on the internet.