MySparrow, you mean like when the cartoon character (I think Pepe Le Pew?) gets smacked by Cupid’s Acme mallet, and has hearts circling his head instead of stars and birdies? 
Belplosh, wow, that’s some pressure to be under! Heck, just driving solo in a parade with that little experience must have been pretty tough.
Yip, the post is too old, so it got removed, but Thomas can explain it/point you at some plans. Basically, you connect rope or reins to 2-liter soda bottles filled part-way with water or sand, running through a wooden board. It lets you practice taking a contact and releasing, and getting more independent with each hand, especially if you are going to drive more than one horse at a time (I haven’t tried it with more than one set of reins). I hope you find a good trainer to work with you and your Haffie - can you work with the same one from last Fall, or are you in a different area now?
I’m just SO glad that Ironbessflint explained how to use the driving whip to help the horse bend! I found a couple of articles that covered it in more detail, so I felt much more prepared once I got there. The instructor covered it a bit, too, but feeling like I understood the concept ahead of time really helped me get smooth turns with the horse working into the outside rein instead of pulling his head around, and keeping him straight (on the line of travel) both on bends and straight-aways. It was fun navigating around puddles and stuff - just shifting our line of travel enough to avoid them, and asking him to straighten onto the new path. We did a couple of turns in the road without enough room to do a normal U-Turn. I watched the instructor first, but he didn’t specifically talk me through it. I found that thinking of it like TOH, only with the entire unit including the cart made it work perfectly. It’s probably one of those things that is super easy and obvious to anyone who’s been doing it for a while, but I was pretty happy I figured it out and made it flow so smoothly! If anything, we even did it better than some of the TOH’s I’ve done under saddle. The first time we trotted downhill (with the instructor still in the cart), it felt like the cart’s momentum was trying to snowball and push the pony, instead of the pony pulling the cart (or it just rolling freely behind him). I asked the instructor what to do, and he said just to give a couple of half-halts to re-balance, and it worked perfectly. After that, I was mostly able to keep him balanced enough that we didn’t get the cart running away with the horse feeling, and when I did for a stride or two, we got rebalanced right away. Granted, the slope was less than 5 degrees, and I wouldn’t have noticed it at all if I’d been walking or riding. :lol: I did get the whip caught on the harness a couple of times when I was first figuring it out, and initally held the reins wrong. I tend to feel like I’m struggling with my body, or with the horse/pony to get things right a lot of the time, but the driving just felt really easy. 