Return on capital is a key measure

The decision to buy or sell is the same. If your asset is worth £1m in the current market and you would not dream of paying anything like that then you should sell it.

If you are doing incredibly well and everything you touch turns to gold then be extremely nervous - you are undoubtedly in a boom. And booms end with a bang.

You are only entitled to assume you are smarter than average after several decades of success - anything else may well be down to luck

Surround yourself with people who are highly competent - running a business is like conducting an orchestra - you may not be able to play the tuba but you need to know enough to realise that the tuba player is not very good and replace him

Debate difficult decisions until you can clearly see what needs to be done - then do it.

Forget whose idea it was - your only objective is to win - not massage your own ego

If somebody consistently screws up, get rid of them

This is not a popularity contest - if you know you are right have the confidence to go against the crowd. But be aware that the crowd are very often right and you will not succeed by being contrary just for the sake of it