Of course, much easier than quitting a job that's not right for you is avoiding it in the first place — so it's worth reflecting on where you went wrong so you know what to look out for next time. Job interviews should always give a candidate an opportunity to ask questions of the employer. Many people do not use this opportunity to its fullest extent. Ask intelligent questions that will not only make the interview panel think (after all, they just made you work — now it's your turn), but that will give you a sense of what it would be like to work there.
Ask questions such as: What is your priority for this role, and what do I most need to succeed? Or, as my director, what would be the most valuable thing I can learn from you? And make sure to ask why the position is available. If it is a new role, ask what internal resources are in place to support it, such as executive sponsorship. If the role is available because someone left, ask how long that person was there. If the answer is anything less than a year, ask how long the person prior to that was there. If you see a disturbing pattern of six- to eight-month stints, it is unlikely you will last much longer. The new hire is either getting let go, or running away. You will likely experience the same fate.