Lately I've been having some trouble with Starbuck getting all worked up and squirrelly, especially around the tying posts and the "scary" side of the arena. For instance, for two days in a row she's gone completely crazy when I was grooming her and then the walk from the tying posts to wherever we'll be working in the arena is adventurous to say the least. She no longer barges into me or tries to run over me (yay!!!) but she still prances around in a circle and won't stay in leading position at all, getting ahead of me and swinging her hindquarters around and whatnot. So I've been rereading everything from my Resources page on teaching your green horse to lead and looking for new tactics.
My mentor Marina (and John Lyons for that matter) say that this is normal for a young horse, that they'll do well for a few weeks or months, then get worse, then get better, then go not so bad and only after all that will they finally internalize a skill or cue 100%. So I guess she's just on the downside of her overall learning curve-- that and we've had a lovely, windy, sunny and crisp winter so far-- just the kind of weather which makes even the retired 30 year old lesson horses kick up their heels.
Anyhow I found this video from reining trainer Jodi Wilson which I liked due to its somewhat novel premise: you teach your horse to lead backwards with her head down and in line with the human's shoulder, then start taking a few steps forward. I especially like it because of the importance it places on your horse's posture when it backs up so that it doesn't turn into a flight response or cause your horse to hollow out his back which can lead to soreness and bad habits under saddle. Hope you enjoy it, I'm going to give it a try by working around the arena towards the scary side!