I've sat and thought about it and tried it and learned that if you open the top portion of a double hung window about an inch or two on both floors of your house, keeping the bottom window closed. Turn on the attic fan and your ceiling fans if you like. This allows the heated air near the ceilings to be forced up by the pull from the attic fan and the ceiling fans and the heated air escapes from the house outside or into the attic and the cooler air to drop into the rooms.
Keeping the bottom double hung windows closed keeps the cooler air in the rooms. Remember cold air drops and heated air rises. Also keep the ceiling fans counter clockwise in the summer. As long as the humidity isn't high this allows for the house to stay cool well into the 80's and to be cold enough for blankets during the nights.
Source: From oldies who lived in the past without A/C
Will have to try this one, although I have some that won't open from both ways, but that's the breaks of an old house!
For the warm months, we have our ceiling fans running clockwise. During the winter, we run them counter clockwise.
Remember to push the screen up too or you will have mosquitoes and other unwanted critters in your home.