(image courtesy of Pottery Barn)
Clear the clutter. Grab an empty laundry basket and anything that doesn't belong should be placed in the basket and put away. This should take 5 minutes.
Look around. Do you LOVE your nic-nacs? If you have something sitting on that table that you think is U-G-L-Y you ain't got no alibi you ugly...duh...duh..you ugly. Take that ugly stuff that doesn't make you happy and put it in a trash sack labeled yard sale and get it out of your house. I'd venture to say you are going to enjoy a simplified room more than one filled with stuff you don't like anymore. Try to think outside the box on your stuff. Can it be given new life with a can of spray paint? Try putting it in a new place to see if it looks nicer there.
Get your can of Windex & Pledge. Polish everything up.
You are going to smile after you do this.