I started by being off leash in just Obedience (and Rally O) and using left, right, back-up, forward and such when i was beside them. From that I started working off leash from behind or either side and even in front. I found getting Annabelle to stop wanting to heel was initially the most difficult, but i never had that problem with Katy. Must be Annabelle's insecurity I have never used a halter , just a long leash on collar if I was in a new environment or at events where there are a lot of potential unpredictability's. I have found my off leash obedience the best to start with. I also used a harness without pulling anything and went on to putting light weights on the traces. On to the cart.....
We do both horse and dog drafting, we have used off leash training for our dogs, but just regular long reining for our horses, though we also use words "get-over" (left) and "come-over" (right) and "whoa" and "giddup" or click. We also use the touch of rein on their backs and still the feel of the bit. So to me horses are slightly different. Some of our horses go on words only, because they have learned to listen. We had one Johnno, who was purely on the bit, from his previous teachings, he was heavy
We love drafting and Annabelle loves it the most. I think she feels special when she has her cart behind her
JUst had to show-off a proud looking Annabelle last Christmas, polishing the cart again for the same jobs