is a great book by Edward De Bono. As usual I'm going to quote from a few pages:
An expert is someone who has succeeded in making decisions and judgements simpler through knowing what to pay attention to and what to ignore.
Simplicity means focused effort.
The human brain is a very simple system that is capable of working in a complex way, rather than a complex system.
Simplicity is a unification around a purpose.
The main aim of communication is clarity and simplicity.
Because [valuable] ideas are 'logical' in hindsight, we have always believed that they could have been reached by logic, with no need for creativity. This has been the prevalent belief and it is totally false.
Much more important than simplicity as a value is simplicity as a habit.
Simplicity before understanding is simplistic; simplicity after understanding is simple.
Simplistic often means jumping from an observed phenomenon to a direct and simple explanation, missing out all the true complexity of the situation.
The purpose of concepts is to breed concrete alternatives for action.
There is no one right answer that suits all situations. It is a matter of being aware of possibilities and then designing an approach that fits a particular need.