One basic way is to ask your interviewers what they like about their job. You're going to get a positive response, but is it hand-wavy or specific? Is it too specific, like they're just cherry-picking the one thing that keeps them employed there? Is there light in their eyes or are they reading a script?

Another way is to ask how decisions get made. Again, the specific answer is going to probably be something pretty non-controversial, so look for the subtleties.

Sometimes it's just obvious that it's too risky. I had one interview where the hiring manager's boss managed to freeze him out of his own loop. I ran from that one.

Also, you should be very skeptical if you felt like your interviews with individual contributors were lukewarm or poor but you still get the offer. That's very possibly a boss overriding flags from his team, or a team that's deadened enough to not throw flags in the first place. If you don't feel the interview went well, trust your gut--might not be just your fault.