Other than telling a child to stop looking at you with that scowl on her face, and singing the Arky Arky song, how can you get a child to stop her scowling?
First of all, if you play the Arky Arky song often she probably has a reason to scowl! Secondly, I've found that the best way to handle a scowling child is to ignore the scowling and proceed as if everything's hunky-dory. Sitting and scowling (arms crossed or not) is a pretty darned passive-aggressive way of saying “Go on, I dare ya, ask me what's wrong.” Millie don't play passive-aggressive. Go do something fun; watch a funny YouTube video, torture the cat or something. If it draws her out, well and good; if not, at least you've done something fun!
How do you get your child over the fear of her toilet?
The first time Joy sat down on her little potty chair it tipped over and she wouldn't go near it after that. I solved the problem using one of those toddler seats that clamps on to a regular toilet seat (like this one: http://www.target.com/Ginsey-Sesame-Soft-Potty-Seat/dp/B001PHBFWO ). Since your daughter is not afraid of the Big Potty, this might work for you; a side benefit is that you don't have to empty a potty chair. You also don't have to worry about making the transition from potty chair to Big Potty.
Do you aim to do things "better" with each new child, or do you shrug and muddle through as best you can, even if nothing changes?
A little bit of both, I guess. My basic approach was the same, but I learn a little more with each child and use that information when dealing with subsequent kids. There's still some muddling going on, but by this point I have a toolkit of techniques that frequently work and a blacklist of things that NEVER work. John Wilmot said, “Before I got married I had six theories about bringing up children; now I have six children and no theories.” There's a lot of truth in that!
What are your thoughts on spoiled milk: "eh, who cares?--it won't harm the child," or "omg, DISGUSTING, don't let it happen!"
Disgusting. Don't let it happen!
Why is it that I can use half a diaper wipe to clean a newborn behind, but my husband must use two full ones?
Your husband has never gotten anything worse than baby poop on himself . . . for him it's Toxic Waste and he wants to put as much substance as possible between it and himself. For you, eh . . . it's just more poop!
What sort of adjustments should parents be ready to make when the kid turns 18?
We have found that a lot of the time 18-year-olds won't realize that they're supposed to be more independent unless you tell them so. You both should review basic house rules in light of “adults sharing a home” rather than “parents and minor children,” though of course since it is your house you still have the final say.
We shift the emphasis from “asking permission” to “keeping your housemates informed” and make a point of telling the fledgling adult when we'll be away and when to expect us home, as well. We have a house rule that adult children who are in school may live at home free of charge as long as they continue to contribute to the household by doing chores. When they have finished school there's a short grace period while they find their sea legs, as well.
Probably the biggest adjustment I had to make was remembering to stop giving unsolicited advice; though I have gotten pretty proficient at maneuvering the younger adults into asking me what I think they should do!