Requiring you to "surrender to the guru" is a red flag. Attempts to impose "groupthink" or to "break the ego" are a red flag. Restricting reading material to that produced by a single author is a red flag. These are some of the warning signs.
If you think about the typical church experience, that might help you tell what's a cult and what is just a spiritual community taking inspiration from a teacher or clergy member. In most churches, people go once/week, take inspiration from a sermon, and go home. There's no enmeshment with others in attendance, or with the priest. Even in a bible-study group, there's usually (except in fundamentalist churches) no pressure to conform, rewire members' psychology, etc.
That's the type of group you should be looking for. They shouldn't be that hard to find, unless you're looking at Hindu groups, which do tend to have a hidden agenda. Some Buddhist traditions are more prone to that than others, as well, but there are still plenty of groups that are simply about studying the principles of the tradition, nothing more.
If you think about the typical church experience, that might help you tell what's a cult and what is just a spiritual community taking inspiration from a teacher or clergy member. In most churches, people go once/week, take inspiration from a sermon, and go home. There's no enmeshment with others in attendance, or with the priest. Even in a bible-study group, there's usually (except in fundamentalist churches) no pressure to conform, rewire members' psychology, etc.
That's the type of group you should be looking for. They shouldn't be that hard to find, unless you're looking at Hindu groups, which do tend to have a hidden agenda. Some Buddhist traditions are more prone to that than others, as well, but there are still plenty of groups that are simply about studying the principles of the tradition, nothing more.