You can do what I do and follow 3 rules that I recently created.
Rule #1. I only watch one trailer and that’s it. Oh and no five minute trailers. I give you two minutes and I won’t watch anymore. That means covering my eyes and ears for anything else(ridiculous but works every time).
Rule #2. No commercials. It’s the easiest way to give away every highlight of the movie. Change the channel or if u dvr fast forward.
Rule #3. No reviews or sites covering film news a day or two before a movie I want to see comes out. They love to give their reviews away in the title of a post and I like to formulate my own opinion before I take someone elses.
Try them out. It’s not foolproof and you will still get let down, but it’s a step in the right direction. Who knows maybe the studios will take notice and take things down a notch.