Good stuff! Thanks y'all.
I think one issue with cooling my house is that I have casement windows. From some comments and things I've read, double hung windows are better at letting you control air flow. If I have to replace windows at some point, I'll likely go with double hung, but that's a far future thing.
tyler.close, I like the idea of something on the outside of the house, but a roller shade would likely just get beaten to death by the wind and keep me awake at night unless there is a good way to really secure it. Shutters would probably be better, but damn, they are expensive, and, one window is super high and another window is in a door and shutters would seem awkward there. Still, it could be worth it; cheaper than a minisplit...
J. Boogie, I am curious about your minisplit. What kind of climate do you live in? Where I live can be humid, so even though it's not as hot as other parts of the state, the humidity is often what keeps me from sleeping well in the summer. I'd really like to avoid installing a minisplit, but as I get older, I have less tolerance for clammy sleeping. Do you use it for heat as well?
MrSal, my attic (or attic-like space) is insulated with fiberglass bats (R-30 is what code requires, I think), but I wonder how those hold up over time if critters get up in there and make nests. It's not a large space and I can't get into it, so investigating this would be a major thing that probably won't happen unless the house starts getting super cold in winter.
So for the high upstairs window, I'm thinking something interior works best. For the downstairs window, lots of things could work. For the door, maybe a screen door with the solar screen in it? Plus lots of beans :)