Whether you decide to hire a Interior Redesign professional or drag your furniture around yourself, rearranging your furnishings is the most immediate course of change. Try to keep an open mind. Your sofa does NOT have to be placed against the longest wall. Consider repositioning all your large upholstered pieces.
Changing or rehanging artwork on the walls will go a long way in creating a new feel for your space. Try laying your wall groupings out on the floor before actually taking a hammer and nails to the wall! If the grouping is going behind the sofa, lay your pattern out on the floor in front of it. This is a great way to visualize the new look and not cause unnecessary damage to your walls!
Treat yourself to some fresh flowers or a new live plant! After a long winter it is a welcome introduction to spring. Every room should include a living plant to feel warm and inviting. Unless you are like me (and kill them) then buy a nice silk. Speaking from experience, Jo-Anne Fabrics carries a beautiful assortment!
Try to be creative and mix/change items from other rooms to create a beautiful "new" look that won't cost you one penny. A few simple changes can and might make a dramitic impact without spending any money at all! My mother in law rearranges her room every spring and fall. She also changes her curtains seasonally. It makes her "feel good" and can do the same for you!