If you know exactly how you are going to start to think about something the rest follows much more easily.
Ask the question:
Where do I start?
You choose from a number of possible operations, many of which have been covered in previous thinking lessons: PMI, CAF, C&S, AGO, APC, FIP, OPV, recognise, analyse, compare, select, find other ways, etc.
Which operation you choose depends on two things:
1. The type of situation.
2. What you want to end up with.