Zing For Just
Pier 1 cushions
Handmade pillows at Etsy
West Elm throw pillows
Bullseye pillow cover
Chiasso's Glitz pillow
Home decor accents such as throw pillows and area rugs can often be purchased at reasonable prices, but offer an instant update to any room in the house.
Add bold cushions -- like those shown above -- to neutral couches and chairs. You can also buy just the cushion covers (think pillowcases), and repurpose your tired throws.
At the same time, consider tossing area rugs onto hardwood floors -- or even carpets -- that have seen better days. (Be sure to also get a non-slip pad if you're using a throw rug on any kind of hard floor surface.)