Sensitizing Yourself to the Mess
One of the things you will notice about really obsessive tidy people is that they seem to be unable to not notice the mess around them. For the rest of us, those stacks of magazines just sort of become background noise after a while. But the obsessive notice them every time they see them, so they are more likely to sort them and put them away.
You can use this to help yourself learn how to be a tidier person. It's actually quite easy (and easy to go overboard). Pick a type of mess, like dirty dishes all over the house. Pick only one type of mess, and make it fairly simple, because this is really going to get to you. Start small: if your house is awash in piles of paper and you insist upon trying that first, choose a subset like magazines. Now walk all over your house looking at dirty dishes. Stand in front of the sink and really look at the pile there. Just see it, rather than glossing over it. Every time you come into the kitchen, look at the pile of dirty dishes. Count them, if it helps you keep aware.
You don't need to do anything, but for the next week, look for dirty dishes everywhere. Notice the used coffee cup on your officemate's desk. Watch how busboys handle used dishes at restaurants. I guarantee you, after spending that much time sensitizing yourself to the sight of dishes, you will want to go around and pick them up, and you will notice them much sooner. Eventually, you will get to the point where you just can't stand to see a dirty dish abandoned in the living room, or a stack of dirty dishes waiting to be washed or put in the dishwasher.
One warning: go slowly. Choose one type of mess and stick with it until you feel like it is internalized. Then move on. Don't do one type of mess a day, or even week, or possibly even month. You're changing how you think, and how you see the world. Of course, if noticing dishes also sensitizes you to paper napkins or something else, go with it, but don't push yourself. We're not trying to induce psychotic break here.