Thing 1 is awesome about helping for short periods of time when I need him to. However, there are certain things he really needs to do on his own and do so regularly. One of them is picking up his toys at night. Thanks to my sister coming to visit, his room is clean. Also, by some miracle on that visit, he has developed the habit of cleaning his room before bed. I can't sit on the floor to read him a book, often bringing Thing 2 in there as well, if the floor is covered in toys.
He also keeps his toys picked up around the rest of the apartment, which is really how the nightly picking up started I guess. We always asked him to put his toys back in his room before he went to bed, and now it's habit.
Thing 1 also puts his own clothes away in his dresser. I fold them, put them into one of those pop up hamper thingies, and he puts them away. Since he dresses himself, he has his own "organization" method for his clothes, which I do not mess with. When he gets dressed in the morning, he makes sure to put his dirty clothes with the laundry now. He used to just throw them amongst the toys on the floor in his room, so when my sister convinced him to clean it while she was here, I had a TON of laundry to do to catch back up for him.
Putting his own dishes in the kitchen when he's done with them is another task he seems to actually enjoy doing. Plus he'll grab a diaper for me if necessary and keep Thing 2 company if he's being particularly socialization-needy so I can do things like go to the bathroom.
All in all, Thing 1 is quite the responsible little pre-kindergartener :) And I only see him getting more responsible from here on out.