We have two inch wood blinds but even they heat up and act like a radiator heating the room.
IMO, the best way to keep the heat out is stop it at the window. Or better yet, stop the heat outside the window.
We live in a west facing third floor condo so we get a ton of afternoon sun. Outside awnings or shades wouldn't work for us but if I was in a single family I would go with awnings AND the film. If I had the right set up, I would fashion or build a temporary shade that could be removed in winter. Maybe some colorful canvas and shaped like those outdoor sun-shade sails anchored to a couple decorative posts that could double as a bird feeder or clothes line..
We have a skylight we are now covering with landscape fabric. We thought about buying an inside shade but they are expensive AND they only stop the heat once it's inside. The landscape fabric looks neat as it shows a honeycomb pattern. We have a flat roof with easy access so putting it up and taking it down is no problem.
The window film is a two person project so have a helper. It's kinda like hanging wall paper. Make sure you buy the kit that includes the soapy? water in a spray bottle and a razor knife and a plastic straight edge (very similar to a wall paper kit). The kit is sold next to the film at Home Depot.
We thought about removing the film in the winter but it's kind of expensive and not REAL easy to do. We figured it's a comfort issue in the summer so the little heat we passive heat we miss out on is worth it. Also, we keep the shades down even in the winter to keep blinding sun out anyway. With the film we can open the shades and not be blinded.