How do I get the heat out from windows during daylight hours?

I have had to do this for most of my clients. The easiest and most effective is to install lined drapery that you can close and open as needed, works for cold too. The next is have windows treated with uv film. Unfortunately the darker the tint is best but doesn't look very residential. The last one I can do in upper windows like clearstory is use stained glass.

Shades help..

Unless you can afford to upgrade your windows, lined drapes are the best. That is what I use as I replace my windows one side of the house at a time.

If you don't have a budget for nice thermal drapes or honeycomb blinds (my first choice is the honeycomb blinds) then get a dark colored flat sheet and hang it floor to ceiling cover the entire window area. You will be amazed at how well this works as long as you close them first thing in the morning before it starts to get hot

Solar window screens, can reduce the amount of sun radiation through window as much is 90%.

There is peel and stick window film that can absorb a lot of the light and heat!

I did this and it works and pleasing to the eye.

Shower curtain.

Heavy lined curtains help a lot. Close them when the sun is coming through and open them when it isn't shining in them anymore. My mom would call it "chasing the sun." A ceiling fan would help, too.

I put up shade sails in front of my two story windows, worked miracuously well!

Blackout drapes..absolutely worth the $$$$

I have insulated, or thermal curtains in most of my windows. The other windows are protected by large trees.

I've done plenty of my disabled clients windows using heat relective window film..... you just cut to a little bigger than the window, spray window with soapy water, and then add your film, use a large plastic spackling tool to smooth it firm to the window. Then use a ruler and box knife to trim to the very edge of the window. I get the film on Amazon, it comes in varying widths and lengths, and 4 color tints..... https://www.amazon.com/s?k=heat+reflective+cling+window+film&crid=3DQTE7N9UUS7Y&sprefix=heat+reflective+cling+window+film%2Caps%2C434&ref=nb_sb_noss