First of all accept the decision gracefully; it will save you a lot of emotional drain and also give you enough peace. Go through this experience as a learning phase. No wonder 'silent' and 'listen' have the same alphabets.

Having accepted, don't judge your new boss from a negative mindset; look at what you can learn from him/her.

Don't keep discussing with others in the organisation as to why this happened and seek their sympathy. This will show you in bad light.

Instead of asking yourself where else wrong, ask yourself where else you can improve.

Don't become cynical of any new system the boss likes to implement; instead politely bring out the pros and cons of new system and suggest alternatives. You will be respected.

Even when one of your juniors speaks ill of your boss to you, don't encourage him/her. Extend whole hearted support your boss in all his endeavours.

You respect their experience; mutually aligh with both your expectation and style of functioning

Ensure the differences in the thought process, if any, are handled in a professional manner; else it will reflect poorly the maturity levels of both of you.

While you take key decisions, involve them. This would make him feel that they are important and their inputs are respected. They would try to reciprocate the same.

Give enough space to them to act independently.

Never judge anyone while he/she may be emotionally down, he/she will still be mentally strong to perform any job.

Every guy has both right side (positive) and the wrong side (negative). It our responsibility to identify the strengths and learn to work with the right side.