Any activity that needs a sharp mind, I try to do early in the day. For example, I find article writing hard so I try to write early. As the day goes on, and I feel myself developing writer's block, getting tired, bored, etc., I move on to surfing a few forums. Taking part in forums still requires some intelligence, but I feel posts are not judged as hard as writing a formal essay (article). Later, as I get even more tired, I might move on to directory submission. Directory submission doesn't require any thinking at all. All my material is saved in a text file, so it is just a matter of copying and pasting into the directory submission forms. I can do this half asleep. Plus, the value of directory submission is questionable. So if I don't do any at all in a day, no big deal. That is another reason why I do it last. (But it is sooooo easy.)