As someone who is currently working in employment law (So I'm not exactly the expert on the executive side) I'd say that make sure you keep a keen eye on what else is out there, if other companies like yours are putting up lots of jobs then the industry is healthy and you typically have less to worry about from a microeconomic standpoint. I have found that when a company is doing badly, either their industry is bad and suffering across the board, or there are some obvious signs with people leaving.