If you have an electric dryer . . . vent the warm and moist air into your home during the winter instead of outside. Read the information in Tip Hero for better details. They have things that you should watch out for, and more detailed instructions on how to do it. What I did was unhooked the tube thingy from the outside vent, rolled up and stuffed a towel into the hole in the wall so cold air won't get in and defeat the purpose. Then I put an old knee high stocking over the end of the tube that would be blowing air into my home to catch the lint. It works great. You have to check the stocking regularly for built up lint. I had water on my floor a couple days ago, and I think it was just time to clean out or change the stocking. (It wasn't much water, but enough to know something was wrong.) The other thing you have to watch out for is that if you get too much humidity, you have to worry about mold. Tip hero tells you how to measure that. Personally, I'm not worried about that because the air in my house is super dry throughout the entire winter. I don't know exactly how much it's saving me. But I hope the heat isn't kicking on as often when I do laundry.
But all in all, I think it's a positively excellent idea. It smells nice too. And if I'm already using the heat to dry my clothes . . . might as well use the leftovers to heat the house, however small the savings, it's good to recycle!