Developing eye for distances?
I've recently gotten a fabulous little all around gelding who was a 2'6-2'9 jumper, and I'm a (mediocre) low level dressage rider. He's needed lots of work (as have I) to adjust to contact and work on the flat, but today I took him for a spin in the jumper tack and WHEEEE! So much fun! He went very nicely in it, and I'm confident in my position and ability to get out of his way over (small) fences, but I have ZERO eye for distances, so I only trot in (though a couple times he throws in a stride or two of canter before takeoff).
I've seen video of him previously and watched a barnmate canter him to fences, and he seems pretty forgiving if you're a bit off, but obviously I don't want to ruin a good horse with repeated bad distances, even to small stuff. I'm thinking I'll throw down poles and count like a maniac, but specifically what else can I do? Will it help me to walk lines more? Or specific exercises?
I do have a fabulous coach, though I don't think we'll touch jumping for a while, as the focus is on his flat work and my talented barnmate/friend will keep him going over fences beyond my trotting x rails for kicks.