" The ABCDE Method is a powerful priority setting technique that you can use every single day. Here’s how it works:
You start with a list of everything you have to do for the coming day. Think on paper.
An "A" item is defined as something that is very important. This is something that you must do.
A "B" item is defined as a task that you should do. But it only has mild consequences.
A "C" task is defined as something that would be nice to do, but for which there are no consequences at all, whether you do it or not.
A "D" task is defined as something you can delegate to someone else.
An "E" task is defined as something that you can eliminate altogether and it won't make any real difference. "

― Brian Tracy , Eat That Frog!: 21 Great Ways to Stop Procrastinating and Get More Done in Less Time