Remember, Wheels has a lot of difficulty finding a consistent contact in the beginning of the ride. You need to always keep the training scale in mind when training horses...rhythm and relaxation, suppleness, contact, impulsion, straightness, collection. I believe many people think suppleness has to do with bending the neck and pay very close attention to their horses heads and necks. They forget about riding the body. Wheels was all over the place. Unfortunately, it was very difficult for the rider to understand that the bit needed to be still; instead, if Wheels wiggled right, she'd correct him left, if he wiggled left, she'd then correct him right and so on. If he'd hit the bit in the slightest, she'd completely release. If she suppled and he softened, she'd release as a reward, but then he'd begin to wiggle again. All of this movement, of course, caused him to come on his forehand and remain behind her leg for the duration of the ride. Fortunately, this provides a really good learning opportunity...
The next day was a bit windy and the horses were all being silly. Wheels was WILD! He was leaping in the air just trying to walk over to the indoor. Nonetheless, I jumped aboard and proceed to leap in the air with joy. He was also being quite resistant by spooking at the dumbest things (such as the big white wall that I cleaned the night before). What fun.
At first, he would turn his head to look at something and wind himself up more, so I'd bend him away and try to go forward. This went on for a couple treks around the arena before I realized I was becoming my own worse enemy. Bridge your reins and ride forward. Create a channel for the energy to flow between both legs to the quiet bit. Just find peace with the bridle and go forward. I produced a "box" between my legs and hands, packaged him up comfortably and set off in a forward trot and canter with no more issues.
Once you establish this straightness and quiet contact, then you begin working on movements and suppling exercises. Remember, the training scale does not mean you can only move to the next tier if you've mastered the one below, they all work hand in hand, together!