And, our final tip from a single dad, Marc Pickett...
This is a recent discovery. I found myself getting into the habit of speaking sharply to my kids to get them to listen: "Get your pajamas on now!" or "I told you not to throw marbles inside!". I did a little internal digging and realized that I wasn't doing this so much out of anger but because it works to get kids to listen (at least temporarily).
I came up with a new strategy that seems to be better. When I've asked my son nicely for the 20th time to put his dirty clothes in the hamper, I'll say calmly "Rhuark, I've asked you several times nicely, and I don't know how to get your attention without yelling, but I don't want to yell. Do you want me to yell? No? OK, let's figure out how I can get your attention without yelling."
That usually does the job. He'll often say "Sorry, Dad, I couldn't hear you.".