A great idea, to start with, is use of mirrors. Well appointed and well placed mirrors can make a huge difference in the space, giving the impression that space is bigger. Mirrors reflect more light as well, thus, they can be a money saving option, allowing you to use less lights.
Organizing small spaces is an art form; you need to get rid of all big and disproportional pieces of furniture, creating some new space. Invest on things that offer you additional storage space without being bulky or heavy and without looking inappropriate in a limited space: coffee tables with enclosed or hidden storage places, while a sofa – sleeper or a futon can be an excellent idea for your living room, if you want to have an addition bed at any moment.
When living in a small space, you need to make your space reflect your taste while meeting your needs. You need to aim for every single inch in the house that can be a useful and useable space. Even if not living alone, you need to have a meeting, set up priorities and decide on how you can organize and sort through your space, so that it open, warm and livable.