Rule 7. Throughout your doublings, you will need several different strategies. It's obvious that the strategy for turning £1.28 into £2.56 will be different from the strategy for turning £160,000 into £320,000. Because of this, rule 7 (the most important rule) is: Don't worry about how you are going to manage future doublings. Concentrate only on the current doubling.
Thinking too far ahead will discourage you. Avoid deadly thoughts like this: "Sure, I can double £5 into £10, but how am I going to double £40,000-£80,000? It's impossible. I may as well give up now."
Rule 7. Detail. More than anything, this is an exercise in mind power. You can ruin your chances of success if you fret about step twenty whilst on step three. It will stop you progressing. You'll be thinking: "This is nonsense. How am I going to turn £80,000 into £160,000? I can't do that!" And this whilst you are on step five - trying to turn 16p into 32p!
As you progress, the next step will seem easy. For example, having successfully turned £5,000 into £10,000, you'll have some good ideas about how to turn £10,000 into £20,000. But you won't have these ideas whilst you are several steps before this - so don't worry about it. Concentrate on the step you are currently trying to achieve, and ONLY on this step.