A vacuum pump failure in IMC leading to loss of the AI and DI has got to be close to the top of my list of nightmare scenarios. Limited panel skills are taught and they're undoubtedly important, but you need to recognise the failure too - and that's my nightmare.
All you can do is to try and learn to constantly cross check what the instruments are telling you. If the DI says you are turning, does the turn coordinator agree? Straight and level on the AI, are the altimeter/VSI and ASI stationary? Do this all the time and you may catch an instrument failure before you follow it in to trouble. It's very hard though.