I've a three bedroom apartment, and one air conditioner in my "storage room" (it was the previous tenants kids room). I've never used it in the three years I've been here.
I just recently got my very first fan for this apartment and turn it on usually around dinner time for the night in the bedroom.
On the days where I am home for the day, I usually do pull the curtains on the side of the house where it will get the sun for most of the day to try to keep the heat out.
At night on those REALLY hot nights where it is just too hot to sleep, I take a damp towel and sleep under it and that is usually makes me cool enough to sleep. It's cheap and oh so very effective. Or I wet my shirt which seems to work a little better as then I don't worry about it falling off.