here's some tips from many hot years in southern california (living in old apartments with no insulation and no AC)

if its possible, put a good box fan in the window of the shady/coolest side of your apt/house. i've got fans on both sides of the apt. in the morning i use the one on the cool side (west). and in the afternoon i pull in air from the one on the (east) side, and at night i use both. it sounds like a hassle but it really does work. make sure you've got good airflow.

get a vornado/cyclone type fan that sits close to the floor. point it up at an angle so it draws up and ciculates the cooler air.

if you can afford it, buy the cheapest air conditioner you can (home depot @60-70 bucks or less). just put a fan in front of it to help move that cool air. i had to buy a very small AC so that it could fit into a very awkward window (1950's building) with a very limited budget. i shoved it in there and used styrofoam and duct tape to seal it up. looks terrible but it works.

hope you stay cool!