The first idea I liked was about arranging furniture. Most people like to shove furniture up against the walls to maximize floor space. However, this often breaks the natural flow of the room. Think about using a couch, desk or table as a room divider or partition. Look at some great examples from William Paid:
The third page of the article offers two great tips, that I suggest often to those I work with:
1) Go vertical!
2) Use multi-tasking furniture.
The fourth tip in the article is one that many organizers work within, but most people never think of on their own: Make your space work for you. The example given is that if you don't eat in your kitchen, there's no need for a table in it; use the space to better suite your needs. I saw a fantastic example of this in Time Out Chicago's September 6 article about living in incredibly small apartments in the city. This gentleman put his bed in the kitchen, because that's where it made sense for him. Not too common to keep the bed in the kitchen, but it fits perfectly and works for him.
Keep in mind, chances are you have enough space to make the place livable. There might need to be some purging of things you no longer need, and some rearranging of what you know you love. But, we can always make it work!