i actually HAVE a/c's I just can't afford to run them.  So i do all of the above, and run the a/cs only on days above 90º, and then only in the early a/m with the apt closed up tight. when the house gets down to a reasonable temp, I shut them off. (approx 2-3 hours)  then i don't have to run them until the next time it threatens to get overly warm.   but keeping the shades down and windows closed keeps the temperature from fluctuating wildly.