First I stuck a big round fan in my front door and blew all the air out of my house. Kind of like the "blower door" concept. This caused air to be sucked into my house. I went around with incense and from the smoke, saw where the air was coming into my house. Exhaust fans in the bathrooms and ceiling light fixtures were the worst culprits. Menards guy said to put chicken wire above the fixtures (in the attic) and then place insulation on the wire, keeping it off of the fixtures. Then, I bought some pink styrofoam for $9 for a 4X8 sheet and began cutting it up to place in windows. Doesn't allow sun in, but definitely keeps the heat in. Does anybody else have suggestions?