Speaking of windows... Let's face it not everyone can afford to replace their windows with the new and improved 5 star, energy efficient, three pane, uber windows. So lets go with curtains! A good set of curtains can help keep heat and cold out of your home. Even these can be pricey. We finally got all ours done when Linens and Things went out of business. Which is sad because I liked Linens and Things but a cheapskate has got to save money! Our curtains have thermal backs which helps keep the heat or cold out and they also help keep the outside noise down. Very important since we are living next to a rail road track. The commuter trains aren't so bad but the cargo trains that run at night are horrible. Sometimes I can't wait until my hubby gets a new base so we can move someplace quiet.
Anyway as I was saying curtains can be expensive too so start with the room that you entertain visitors with. Pick out nice ones that compliment your room but have the thermal back or add a second layer with a second curtain rod behind the first.
After that get creative. Hit the yard sales and clearance sales. A twin comforter with Superman or Belle from Beauty and the Beast will work just as well as good curtains and your kids will love waking up to their favorite characters. Knot some baby blankets together for a colorful mosaic for the baby's room and a nice quilt for your window will help keep everyone warm and toasty in the winter (coming soon to an northern hemisphere near you ) and cool in the summer (for you lower hemisphere readers).
When the kids out grow childhood characters then its time to update their curtains with real curtains they are getting to an age where they want to have their friends over an might be embarrassed with Thomas or Dora hanging on their windows. But by now you have had time to hit more yard sales and watch the sales ads so you should be prepared.
You will notice I put the kids curtains ahead of our curtains... Lets face it kids can be cruel and our kids are more susceptible to the taunts of their peers then we are (not to mention not many of our peers will be in our bedrooms) I will not put my cheapskatery above the welfare of my children and it can be hard enough with all we pile on our children with more and more homework and less time to play. The last thing they need is problems with friends too.