From To Do Doing Done: A Creative Approach to Managing Projects and Effectively Finishing What Matters Most:
Think about what happens when you try to deal with a stack of paper. You take the first piece of paper off the stack, read it over, realize you can’t do anything about it right now, and put it back on one corner of your desk.
The next item, the same thing. The next item, you do what needs to be done and then realize that you may need the original piece of paper later, so you put it in a different stack on another corner of your desk.
You are just rearranging the stacks!
It’s impossible to prioritize a stack of paper. When you’re dealing with the stack, the most important item in that stack may be on the bottom … where you may never get to it.
The principle to overcome this is: Operate from lists, not stacks.
If you have any stacks, go through each item in them one at a time. Do what can be done in two minutes or less. When anything can’t be done in two minutes, then put it down as an action item on your next action list and then either toss the paper or, if you’ll need it when you do the action, put it in an action file and pull it out when you get to that action on your list.
If everything in the stack pertains to the same thing and it won’t fit in a file — for example, it’s a set of papers to be graded (let’s say you are a teacher) or the stack is really a big manuscript you have to read (let’s say you are an editor), then put the action which the stack represents on your next action list and put the stack on a shelf — off of your desktop. If desired, put in parentheses after the action item the location of the stack (which is really just “support material” for the action) to remind you that stack exists.
When you choose to do the action on your list, pull the stack off the shelf and do the work. When you are done with it for the day, put it back on the shelf and bring it back out the next time you work on that action.