Bring a bit of nature into your home and work. Plants reduce stress  and anxiety  and increase attention. In addition, plants can reduce the amount of airborne pollutants. Research done by Bill Wolverton at NASA in the 1970s and 80s demonstrated the air-cleaning powers of plants in the Skylab, biospheres, and homes. So add a few plants to your décor.
Nature is full of lovely plant aromas. These not only make our environment pleasant, they are also full of chemicals that enhance our thinking , mood, immune system, and more. In fact, more and more scientists are looking at the therapeutic effects of different plant oils  on various health conditions. Two examples supported by research are peppermint oil, which enhances attention and lessens mental and physical fatigue, and lavender oil, which calms. Try diffusing a few drops of these oils or other oils at home to enhance your mood.
Studies in schools, offices, and hospitals show that letting in natural light increases job satisfaction, enhances performance, reduces depression, and enhances recovery. One interesting study compared the use of pain medications in patients who were on the bright and dim side of a hospital. Those on the bright side perceived less stress and less pain and took fewer analgesics. So let the sun shine in.
Views of natural elements, such as trees, also have a positive effect on mood, attention, and recovery. So if you can’t get outdoors, at least look out, particularly if you are feeling stressed  or in pain.
If you don’t have a view of nature from your window at home or work, you can still benefit from a landscape painting or photo. Find one you like. You might consider a view of an open landscape (rather than a forest), as some researchers hypothesize this is inherently interesting to us while also making us feel comfortable (we can see there are no predators hiding).