I live in the central valley of California, with some hellishly hot summers. And in the summer, we have NO rain at all from spring to late fall. So it gets hot here, very hot.
I made cream colored drapes for my South and West windows and they are like quilts. They have muslin backing with poly batting, sewed to the muslin and then attached at the top and sides. I can see a difference in my power bills since then. And on the front two side windows that are about 8 feet from the house where a single man lives and....well, has company, I painted the windows and glass windows too, inside and out. That was after my 23 year old Granddaughter visited and I heard her commenting to herself while looking out the window before she turned on the lights...."Gosh, I didn't know you could do that!!"
Then I added quilted drapes to them too, it is on the North of the house. Don't need those windows anyway.