1. Technology - Also make sure the place you're applying to is willing to give you the tools you require to do your job well. A company that's willing to pay your (very likely) high salary, but then won't drop $2,000 - $1,000/yr on software tools/hardware that make you more efficient is probably an indication that things aren't great over there.
2. Environment - Your job is not your family. Despite the new-speak, you're not on a team with a bunch of team-mates. You are bought and paid for and the person who paid for you expects to get a return for their purchase. If the environment is bad, leaving is the right thing to do[0] for both yourself and your employer. If you stay in a bad environment, you're miserable and you can't provide your best work where you're not happy. Your employer is better off having someone else do your job and you're better off finding some other place to offer your work. And if it's not just a "bad fit", but is actually a "truly awful environment", sticking around simply re-enforces your employer's mindset that everything's fine.
3. Money - I have a feeling you may take some heat for that statement but I completely agree. You'll hear plenty of people complain about other people having too much money but you'll (almost) never hear people complain about having too much money, themselves -- even at, what today, you might consider "absurd salaries". This advice applies somewhat uniquely to our industry where there almost certainly is an opening out there at a company that both pays well and is the specific work that you love to do[1]. I kick myself for turning down four different job offers over the years and chose, instead, to work too long at my first, serious, job. I let "fear of the unknown" convince me that there's too high of a probability that I'd like my next job less than my current job (and I convinced myself that this actually mattered).
[0] Though I would suggest, first, having a direct conversation about things that aren't working for you. It's not easy to do but I've found it to have positive results. And if it doesn't, it'll help reaffirm that you need to do the right thing and get out.
[1] My ex-wife once looked over at the code on my screen while we were sitting in bed watching television and said "Is this what you do all day?". I smiled, excited that she was taking an interest in the work that I was doing and wanted to know more about it. I said "Sure is" (beaming a little too much). She paused, and in a serious voice that, to this day, I will never forget said "I'd kill myself if I had to do what you do."
