Make sure that at least once a month you let fresh energy circle in all your small and cramped spaces. These could be the aforementioned small room but could also be storage places and spaces underneath stairways. Any energy that circulates smoothly promotes health and positiveness. Any stale non-circulating energy is negative for your health and your spiritual and emotional being.
The easiest way to promote this fresh flow of energy is by opening up all your windows and doors and let good fresh air from outside sweep through your house or apartement.
Other methods to improve fresh energy in your place is to avoid leaving newspapers and magazines piled up in corners, near the stairs or other prominent places. They tend to attrack negative energy because they tend to contain so many negative stories of crime, rape, war and worse. Seeing these brings your attention back to what you read and this in return keeps circulating negative thoughts and images. Of course glossy fashion magazines are not as bad, but they still tend to clutter up if you don't regularly sweep them into the bin.
One of the best remedies for small, cramped places is LIGHT. Use light whereever possible. Concentrate on 5.000 calvin light which is near daylight, not quite as light and cold but has a warmer tint to it. If you have plants in your small places make sure they are well. Don't keep any left-over plants that have previously died.
By changing decoration and paintings regularly you keep a place alive too. Also when using part of the wall for storage, for example as a bookshelve, ensure it is behind closed doors or a curtain as especially books tend to draw attention and as long as there are not uniform looking will bring clutter and confusion to the room.
And where possible keep your walls bright, fresh and clean.