Treat the six hats like a game where there are rules and everyone must
obey the rules.
Only the facilitator can say when the hat can be changed.
A short time should be set under each hat - this encourages focus. Even a minute per person is fine - you can add time if required (easier than setting a long time and then everyone is sitting "twiddling their thumbs").
The red hat time should be kept very short - feelings just need to be stated not justified.
A blue hat should be used to start and finish the meeting:
Blue hat 1: what do we want to achieve? | why are we here? | what is the problem?
Blue hat 2: What have we achieved? | next steps?
A red hat should be used after the first blue hat so that any strong feelings can be aired at the outset.
There are two ways in which the hats can be used:
Method 1 - Random
The meeting starts off and then at some point the chair person says, "I think we need some green hat thinking here". Later on in the meeting he / she might then say "I think we need some black hat thinking here". In other words the hats can be used at our discretion at any point of the meeting to request a particular type of thinking.
Method 2 - Proactive
Before the meeting you can decide a preset sequence of hats that will be used. This sequence can be in any order and not all the hats need to be used. De Bono does recommend however that the meeting should start off with the blue hat.