One of the easiest adjustments you can make would be to work on your windows. Make use of natural lighting. If your living room window receives a lot of daylight, opt for light curtains that allow light to pass through. Alternatively, you could also use blinds. Letting natural light pour into the room would help make a limited living room space feel more open.
Another great window idea would be to use a bay window as another seating area or an extra storage.