We also had foil from the hardware store in the old house, it lasted 6 years without any problems and was left by the next tenant. Applying it was easy (you just have to be careful not to create any bubbles) and you can simply remove the foil later if you no longer like the design or want to "see through" it again.
In our own home, however, we decided on a pleated blind so that you can look outside when needed! However, we treated ourselves to a high-quality pleated blind from the window manufacturer, which was screwed in instead of clamped or glued. It did have its price, but for our own house, I didn’t want to skimp at this point, but rather have something durable and stable.