Among tons of "adj.+noun" compound adjectives, some of them end with "-ed", e.g. open-minded, double-sided, big-headed, some without, e.g. present-day, rear-view, deep-sea. I've also seen the usage of both cross-eye and cross-eyed. Is there any rule for forming these kind of adjectives? If not, does that mean when we want to create a new one, we can go either way?