I've seen free schooling done two ways:
1) with Fifi. She lunges very well and pays a lot of attention to her handler. If she's loose in the school and you go in with a lunge whip and ask her to walk on, she'll just go on a 10m or so circle around you. If you can keep her concentration (

) she'll walk trot and canter on both reins. The trick seems to be acting in every respect as though she is on the lunge, but with twice as much concentration from the handler. Unfortunately I don't think it's something we taught her - we just tried it and it worked (nice for us, but not very helpfull for you.....)
2) with a pony my instructor was trying to teach to lunge. He could just about cope with walk and trot, but canter wasn't his strong point anyway and if you asked him to canter on the lunge he'd just go in a straight line as fast as he could

. For him we used the entire school and had three people (it's a fairly large school). We were all roughly on the centre line - one at each end and one in the middle. The trick here was to stay behind him and keep him moving. The hardest bit was "handing him over" from person to person without someone getting in front and blocking him. It also didn't help that the school had very square corners where he could trap himself (not very bright

).
Julia - does Angel lunge well? If so, lunge her a little, then just take the line away but do everything else exactly the same. If she can't get the hang of that, or if she doesn't do lunging, then you might want to try some version of my (2). Either way I'd start off without the jump and get to the point where you can control her gait, speed and direction using your voice, body language and a lunge whip. This is where I can see a round pen having huge benefits, as the bigger the school and the more corners it has the harder it will be to keep her under your control.
Hope that gives you some ideas - those two examples are the only experience I have, so there's probably a much better explanation out there
Good luck