So, when I learned how to canter, I was taught to use my outside leg, and put pressure on the inside rein. When I got older and started to ride stubborn, more challenging horses, I encountered many who didn't want to pick up a certain lead. My same instructor told me to bend them to the inside and make sure they are looking to the inside to get that lead. I recently changed instructors and was on a horse who didn't want to pick up the right lead. So I did what I had previously been taught. My new instructor told me to have the horse look to the outside to pick up the lead.
So my question is: Which is correct for asking for the lead, having the horse look to the inside or outside and why is that correct?
Also, there is this one horse at my old barn who hasn't been keeping her left lead through a grid. My friends and old instructor have been working with her to make her keep it but she has yet to go thru the grid without swapping to her right lead. Ideas on how to make her keep her left lead?