This I learnt from David Allen.
David Allen developed the powerful GTD (Getting Things Done) program. GETTING THINGS DONE® is a personal productivity methodology that redefines how you approach your life and work. The fundamental is to follow five clear steps that apply order to chaos.
Collect what has your attention
Write, record, or gather any and everything that has your attention into a collection tool.
Process what it means
Is it actionable? If so, decide the next action and project (if more than one action is required). If not, decide if it is trash, reference, or something to put on hold.
Put it where it belongs
Park reminders of your categorized content in appropriate places.
Update and review all pertinent system contents to regain control and focus.
Use your trusted system to make action decisions with confidence and clarity.