Job: Swim CoachTeaching kids to swim was a great job. I coached the age 6-12 group for a few summers in high school while I was on the swim team.
1 - Learning curves should be gentle, but have skippable stepsThere's a pretty huge range in physical strength between a 6 and 12 year old kid, as well as a wide range of natural abilities. I coached some prodigies that seemed to be on their way to state records and olympic time trials, but others took weeks just to get into the water.
It's important to give very manageable steps to someone who's totally new. (Sit with your feet in the water for awhile; now try kicking while you hold onto the wall; now try kicking while I hold you up; now try kicking with a kickboard; now try using your arms too; now learn to breathe from side to side; now learn how to flipturn; now learn how to dive from the edge of the pool; now dive off the starting block.)
However, experienced players need to be able to skip these steps and have something challenging to do too. Juggling your attention between these two groups is very difficult but important.
Job: BabysitterThis was another one of my very first jobs.
2 - Use choices to mask requirements"After we do the dishes, which movie do you guys want to watch?"
Try to always let your player feel like they are making a choice, especially right after requiring them to do something.
3 - It's much easier to manage strangers than friendsKids who've never met you before the job behave a lot better than kids who've known you for 3 years as just some other kid.
It's a challenge to get results from someone who thinks they know better than you do. Include them in the decision-making process and they'll be more likely to respect your decisions.
4 - Players will always test the boundaries of the rules"But Mike, my MOM lets me watch HBO all the TIME! Honest!"
Don't just design the game for how you want players to behave, design it to take into account how players want to behave themselves, which is often quite different.
Job: Math TutorI taught algebra to some high school students, and basic math to elementary school kids.
5 - Always ask people to demonstrate what they've learnedIt's almost impossible to tell if someone has learned a skill or concept properly without asking them to execute it. Kids will just nod and smile when they have no idea what's going on.
Tutorials should ask the player to perform the action they've just been taught, even if it's something silly like moving and jumping. Just make it possible to skip the tutorial entirely.