I installed a attic fan it comes on when the attic temp reaches 85 sucks all the hot air out and keeps the house cool , we also bought some of that reflective window film for the windows that face the sun that helped too
If the nights are cool, keep the windows open, but close them all and draw the curtains/blinds at 6am when the sun comes up. Keeping the sun out will reduce a lot of the heat. At some point in the afternoon, the inside temps will match outside. You can use fans or open windows (for the breeze), but don't let the sun in. Then wait til sunset and start over again.
I bought these window sun screens ( professionally made, installed) placed them on window's that have the sun hot them at hottest time of day. They work wonderful!! My electric bill hasn't been to high this summer even with keeping thermostat at 74.