Tense in とき clause

I noticed many people are confused about what tense should be used in とき　clause. Apparently the textbook explanation is confusing. For now, I want to say only one thing I think you need to remind:
"present tense" in Japanese is not the same as present tense in English. In Japanese, it's mostly a future action. Sometimes it's habitual action. Please have this in mind and go over the example sentences in the textbook again. See if it does make sense now.

For example, if you say　おもしろい映画を見るとき笑います。　This sounds strange because it sounds like you laugh when you are about to watch a funny movie. It's because of the present tense that's saying a future action. おもしろい映画を見るとき　is referring to a point at which you did not start watching the movie yet. That makes me think why are you laughing before you watch it? Is it out of anticipation? It's weird. You should say 面白い映画を見たとき笑います。Or 面白い映画を見ているとき笑います。