These are the basic 10 rules but if you want to know more get the book... ;-)

Law 1: REDUCE.- The simplest way to achieve simplicity is through thoughtful reduction.

Law 2: ORGANIZE.- Organization makes a system of many appear fewer.

Law 3: TIME.- Savings in time feel like simplicity.

Law 4: LEARN.- Knowledge makes everything simpler.

Law 5: DIFFERENCES.- Simplicity and complexity need each other.

Law 6: CONTEXT.- What lies in the periphery of simplicity is definitely not peripheral.

Law 7: EMOTION.- More emotions are better than less.

Law 8: TRUST.- In simplicity we trust.

Law 9: FAILURE.- Some things can never be made simple.

Law 10: THE ONE.- Simplicity is about subtracting the obvious, and adding the meaningful.