I tend to test the waters with interviews every couple of years even if I end up staying at my current job. I've learned three basic tricks:
1) Everything in the job ad except for the technologies listed in the requirements is very likely bullshit. If it turns out the developers are actually a fun group of people to work with, HR could've come in and turned the ad that would indicate this into a boring list of company mission statements, and if the team sucks to work with, somebody from marketing may have gotten a hold of the ad and made it sound like they're the coolest place ever to work. Even the experience level they're seeking could've been edited by somebody who didn't know what the team in question is actually looking to hire (which is where I think a lot of the "junior developer with 10 years experience" things come from - whoever wrote the "junior" part of the ad is not the same person as the one wanting 10 years of experience). But neither of those groups knows enough about all the weird acronyms and technologies in the requirements list to confidently touch that.
2) In the "do you have any questions for me" part, you should ask what their general process is like day to day, and what their process is like when something goes wrong. The day to day question is important - it gives you a glimpse into what the biggest part of the job will be like; but really it serves to open them up for the when-things-go-wrong part. If they don't have an answer to this that they don't really have to think much for (and your job isn't to develop this for them), then the job will be waaaay too stressful at crunch times or when everything's on fire or something.
3) The small talk portion is important, because the questions you're asking are really different from the ones you're saying out loud. I like to ask the interviewer what hobbies and stuff they and the team like to do in their spare time, but what I'm really asking is "do people who work here have spare time". I don't really care if my coworkers have similar interests to mine outside of work (though it is cool when they do), I mainly care if there will be an outside of work.