Keep like items together. If you're organizing the closet don't leave the area to put something away in the attic cause you'll get sidetracked. Finish that area first. This will keep you focused. Pick up and put away items as soon as you've finished with them.
Most organized people make decisions quickly and easily.
I sort it at the mailbox and immediately toss the junk, since I know I won't have time to read it later. I consider my time valuable. I knew I had nowhere to store it. So I didn't buy it. You know you probably will or probably won't.