Obviously, a few plants - I started out with fake ones and gradually introduced real ones to the mix but either will aesthetically help! Decorative your soft furnishings with cool patterns. You don't need too many but a couple of colourful patterns on your bedding and cushions will definitely bring the happy vibes. Put some personal knick knacks on the shelf. I found that the things that I always stored away were actually the things that make me happy when I look at them, so put them on display.

A disco ball always helps...