To use your checklist, simply work your way through it in order, dealing with the A priority tasks first, then the Bs, then the Cs, and so on. As you complete tasks, tick them off or strike them through.
All of us think, plan and work differently. A program that works well for a colleague might not work well for you simply because you learn and think in your own way. This is why it’s useful to research and try several different ways of compiling your checklist before deciding on a single system.
By keeping such a checklist, you make sure that your tasks are written down all in one place so you do not forget anything important. And by prioritizing tasks, you plan the order in which you’ll do them, so that you can tell what needs your immediate attention, and what you can leave until later.
You may find it easier to compile several checklists (covering personal, study, and workplace, for example). Try different approaches and use the best for your own situation.