In your daily life you will probably have to dance among many different tasks. You must learn to do it with the safe net of a solid GTD system!
The formality factor means that some decisions fail because of the apparent complexity of deciding what to do. If you streamline your decision-making with a good system, you will speed up your activities and get rid of stuff.
Keep a big (or giant) stack of fresh folders and a good supply of stationery items. Nothing is more frustrating than putting of your organisation task because you have just run out of folders, paper sheets or whatever item you need.
At a very simple level, the humble lists are one of the most formidable tools to lead a better organised life. But remember that you must follow some basic rules to be able to write effective lists.