Query's list really just covered it all. I'd say my daughter has progressed pretty quickly for the ice time we have available. My job has been to make sure I hit as many of those bullet points as possible to support her goals. She started Basic 1 in November of 2012 and 4 years later (at age 10), she's landing everything up to double flip consistently and working on getting her double lutz more consistent. I never wanted to be the crazy person getting up at 4am, but I hand her that contract every month and she circles every session... so we go to every session we have available (4 days a week at this time of year).
She has made a choice to put pretty much everything else on the back burner so skating can come first. Many kids aren't willing to do that. Parents can push them for a while, but eventually it needs to be their choice. There are only so many times an unmotivated child will get up at 4am before they're done. It's not something a parent can direct or decide after a while. People probably think I push my daughter but she's really a pretty strong willed kid. She doesn't do anything she doesn't want to do. Eventually kids need to be internally driven and at this point, she still is. When she isn't, then we will back off.
1. Some parents don't get their kids to lessons in time, or they miss a lot of lessons. They miss too much of the teaching and in-class practice. This is probably the biggest factor.
2. Some parents don't bring the kids to the ice in between lessons. You can only go so far without practice.
We have two types of skaters at our rink. I call them the "core group" and the "once a weekers." There are 8 or so core skaters who skate every session and stay the whole session. The others show up for 45-60 minutes per week, stay for half a session, and don't spend much time on the ice outside of lessons. There is a HUGE difference between the progress of these groups. This is partially on them and partially just scheduling. Skating is right after school here so not all parents can get their kids there. My feeling is that none of the once a weekers are begging their parents to figure out how to get them there -- they are pretty content with what they are doing.
4. Most kids or parents don't tie the skaters' boots tight enough. This is a lot more common than people realize.
This is a big problem, especially with the older girls who tie their own skates. I usually don't say anything because people usually don't like to hear it, but I had to step in last week with one of the girls. Her dad was in the room and he said, "I keep telling her that..." Coming from me, though, she did it. I was worried for her safety. It takes a lot for any parent here to want to stick their noses in where they don't belong because there is just so much drama. I try to keep my mouth shut about all skating-related stuff. This doesn't help the skaters at all, in my opinion, but it is what it is.
12. Some kids have more "natural talent". Some of this comes from prior athletic activities, like dance and gymnastics. I believe some of it is genetic. You don't need a lot of natural talent to get through BS2. But people start dropping out in large numbers around BS3 (especially if they have trouble mastering outside edges), or can't pass it by reasonable standards. (This differs by rink and instructor, because some instructors have a lot tougher standards than others.) And by the time you get beyond the most basic jumps, some kids can't do it no matter how hard they try. (Neither can I...)
This really isn't a sport you can brute force after a while. You have to be able to keep track of a lot -- which edge, which direction, where your arms go, where your head goes, patterns, where your free foot goes, etc. I don't want to sound mean, but some kids just never get it. I've seen some kids who quit skating because it just didn't make sense to them go on to be very accomplished at other things. A good example of this is one little girl (she's about 6) at our rink who has been taking private lessons every Saturday for a year and she is still not getting forward crossovers. She consistently crosses the wrong way or tries to cross on a straight line. If you're 6 and you don't master forward crossovers in a year, chances are it's not your sport. Some kids take to it like a duck to water and immediately get it, others never do, despite skating for years.
15. Some kids are afraid of falling, and are constantly scared and stiff on the ice. Not nearly as frequent with kids as adults, but it happens once in a while.
You have to be fearless. With the older girls, even if they think they are landing an axel, many are just doing a salchow. The fearlessness is the difference between clean axels and doubles and just doing singles that look funky because they take off and land 1/2 turn short on each side. I think it's super important to start working on doubles before the fear sets in.
Part of this is giving kids the tools to not be scared. I nearly bubble wrap my daughter and we go to great lengths to make her as comfortable as possible on the ice. That's my philosophy. She wears full padded shorts during practice, special boot covers to keep her feet warm, has different levels of jackets for her level of warm-up, etc. We've tried to remove all the obstacles to successful practice. These things make her super productive. She doesn't worry about falling because she's fully padded. She can fall 100 times and get up and keep working. The other girls have pads but they all have the same kind and they all say they don't help at all so they don't wear them.
We think it's also super valuable that my daughter and her coach mesh really well personality-wise. She's not demanding, she doesn't yell, she doesn't freak out and get crazy at competitions. My daughter doesn't need that. She and her coach both have high expectations and my daughter likes to be challenged, but she isn't motivated by fear or anger. She isn't motivated by someone who gets high strung on competition day. There is no right or wrong coach -- just the right or wrong coach for that particular kid.