Number five subdivided.

Anyway, I took this as a sort of challenge and decided to break #5 into seven things, too.  My criteria were that the seven things were not to include anything covered in Nos. 1-4 and 6-7.  (So, even though making your bed is arguably a sort of cleaning up after yourself, and wiping down the bathroom afterwards is too, I didn't write it down.)

Here is what I came up with.  I actually came up with more, but restricted the list to seven.  No reason.  Seven's a nice number.  Thanks to Mr. Covey, it's now got an almost religious-numerology-type association with "effectiveness."

Now "cleaning up after yourself" is not the same thing as "cleaning."  As Jen perceptively noted, "cleaning" is something you have to do periodically because you or other people in your household have failed to "clean up after themselves."  The basic concepts in cleaning up after yourself are pretty simple.  (These are not the seven things.  These are concepts I used to try to develop the seven things.)  They are:

• if you're going to use a thing or an area again, you should make it ready for use.
• if you're not going to use it again, you should discard it (the meaning of "discard" varying with the thing,  encompassing concepts of recycling, trash, putting in the laundry, and charitable giving)
• take steps in advance to reduce soiling stuff or transferring mess or dirt to more things
• clean soiled stuff as you go through a task 
• include "cleaning up" as an integral part of doing any task at all, so that (for instance) you allow enough time for it 
• never assume that someone else will take care of the mess you've made if you don't either do it yourself or delegate it immediately.

Does that cover everything?  

So these are the seven things I came up with.  (Note:  I do not do any of these things regularly, even though I ought to.)  As a bonus feature, the three kitchen things will also lessen your risk of food contamination and subsequent illness, no?

1. Clean up after dressing and undressing.  If an item is clean enough to wear again, hang it up or put it folded away immediately; if it's not, put it into the laundry stream.  Commit to one or the other, don't just throw it on a chair.
2. Clean up after going somewhere in the car.  Take everything out of your car every time you come home, except stuff that is supposed to stay there permanently (maps, emergency kits) and stuff that's ready to go for the next car trip (which should be well corralled).  Encourage habits that make this easier, like kids keeping their stuff in bags, having a trash container, etc. 
3.  Clean up each item on your to-do list as you finish it.  Paying the bills?  Don't save a pile of stuff to be filed, file each item as you finish it.  Doing schoolwork?  Put away all the materials you used for each subject before you start a new one.  
4. Clean up the office, desk, schoolroom, or wherever you do your paperwork after the work session is done.  Sweep up pencil shavings, clear the surfaces, ready it for the next use.  Homeschoolers, get that schoolroom ready for the next day.
5. Keep the kitchen surfaces clean while you're cooking.  Don't put dirty spoons on the counter or balance the whisk on the edge of the pot where it will fall and spray beaten egg everywhere.  Put it on a plate that can be washed, or sometimes disposable stuff like newspaper/foil/wax paper. 
6.  Begin cooking with these seven items ready for use (not hidden away in a cabinet):  (1) apron (2) empty dishwasher (3)  sink full of hot-but-not-scalding soapy water (4) trash can (5) dishrag (6) clean dry towel for dishes (7) clean dry towel for your hands.   You'll be able to quickly clean things, including your hands, rather than let them spread gunk all over the kitchen.
7. Plan to use kitchen workstations so you move around less with messy stuff.  Crack eggs within reach of the trash can, work with raw meat next to the sink,  chop vegetables for sautéeing right next to the stove with the pan ready.

 I'm inspired to try some of this, aren't you?  (The eighth one was going to be NEVER LET YOUR KIDS HELP YOU COOK so I'm glad I stopped early.)

UPDATE:  Seven things to teach your children so they can clean up after themselves.