Overly verbose and "glitter" readme.md files is a good indicator of bad projects or at least projects which need more attention to be used. It's too often pre-rugpull or look-at-me repos where better solutions are one click away.

Finding any curse words in hidden comments in the commit history is for me a good indication of a human working on a passion project, though ymmv.

And there are always exceptions to the exception of the exceptions.

I tend to look at other people involved, like contributors but not just the volume but actual people and their other activity. If the original author is still around and active that tends to be a good sign IME

I usually just read the dang code.