It's a lot like a bhs errr I mean a flik, because it only gets harder to make if you try to do what you think should be done based upon what you see when others do it. Just as a bad bac...flic happpens when the performer makes attempts to get upside down by reaching around with their chin, and is far easier when started by jumping backwards, the glide kip can not be done by making obvious efforts to raise yourself up by pushing the bar down....because it"s a swing skill.
The swing gets killed when kids try to pull themselves up, and that leaves them with nothing to finish the skill with but brute strength......yeah right, like that's going to work. The best and quickest advice I can give you is to consider the ending position of the kip....so where or what part of the body is the bar going to be when a good kip finishes....the lower hip/upper thigh.
Think about that for a second.......if you can get the bar to their hips half the battle is won, even if the bar gets there when thy're still upside down....well sort of. Upside down is pretty hard to define during a kip because it never happens during a kip, but lets say the kids glide has a reasonable amount of extension through the hips, combined with enough swing into the extension that their hips elevate a bit as the forward motion hits it's limit.
If they can bring their toes/feet to the bar using only, or even just mostly, their stomach muscles and hip flexors, with zero to little help from their arms, they will be in a great position to swing from. That position should look like their shoulders are more under the bar than their hips, and the more mass they have on the "hip side" of the bar the better, as it will give them more swing to work with.
As the swing from that position starts, the best thing a kid can do is to straighten their body while holding it near the bar....that's why you hear coaches telling poor little Suzie to "slide the bar up your legs". That's a pretty good correction, but falls short of being the "golden ticket", as that action alone won't help them keep their shins....and then their knees...and then their lower thighs...and then their lower hips against the bar......and if their legs don't stay against the bar...they won't be able to slide the bar up their legs, because their legs will likely flop away from the bar as they try to slide it from their toes to their hips.
So I'll add a mental image of leaning back as they slide the bar along their legs, and tell them that it's kind of like the way you have to throw a ball down in order for it to bounce back up. The lean back is more of a concept than a position, so don't expect to be able to see it happening.
The concept of leaning back does a few things. First it gives them a chore to do at the moment when most most kids "feel" the urge to pull themselves up, and they forget about pulling up for that key instant. Secondly it places their arms in a straight position with their shoulder rolled slightly to their chest, and that's about the most powerfull position you can pull from. Lastly the lean back mental image actually seem to shift their weight toward the bar, which makes sense if you think about it.
Beyond that it's a matter of timing and rythm, as sliding the bar too early or too late won't work so well....and the same is true about sliding the bar to fast or to slow that the motion won't work in concert with the swing energy created with the hips on the "hip side" of the bar at the moment the feet first get to the bar.....
I hope that covers it enough to get your imagination up to the point of filling in all of the little gaps.
Here's another bit of advice about limiting your corrections......Something inside you made you want to do gymnastics, which led to trying to figure out how your body uses motion to make it's way through skills.....and that has led you to the point where you're beginning to figure it out. You got to the point you are today, as a gymnast....and a coach, by using a little advice from the coach, a little guess work on your part...as wel las your coach's part, concentration, and a lot of tiring work.
As a coach your goal is to give a little advice, encourage concentration, urge kids on to do the tiring work, and possibly the most important part.....guessing and reacting to what the kid does with your guess....followed by a second guess, and another....until the two of you get it right. You'll do a whole lot better if you tell the kids that there's some experience and some guessing behind the words that come out of a coaches mouth.....your's included, and that either the experience or guess can be wrong....or right, but that you'll work hard to get it right, and that's about all a kid can hope for.
