Anyone contemplating taking a horse xc should develop a mania about a good front-end style, most particularly, knees being tucked up nice and high. This good habit might well save your necks one day! (This first photo gives me nightmares, but the other photos show that she did improve, a LOT, with the right work.)
Some great exercises to teach a naturally less-than-perfect horse to snap up those front legs better are:
Most obviously, high sided cross poles. Both as a single fence to begin with, and later as the front part of a spread, to encourage straightness as well as a good tuck. Be aware that a X pole with really high sides can be quite daunting/claustrophobic for a green horse.
Short small bounces in a row, you can build up to 4 or 5. Cross-pole bounces are useful.
With the bounces, it is good to alternate the height, i.e. have one end of the pole high and the other on the floor and vice-versa with the next one, through the grid. You’ll feel if the horse is defter and/or stronger one way or the other. You’ll need to use your legs to stay straight!
‘V’ poles onto jumps will encourage them to snap up quicker and stay straight.
In clinics Ginny Elliot used to make us come repeatedly to a small fence (about a foot high, no bigger) in canter and get very deep every time, to teach the horse to snap up in front, and jump up not across the fence. We’d get yelled at if we saw a normal/longer stride… the point of the exercise was to see a really deep one, since the fence was deliberately so small. She swore it had saved her a few times!
Grids with short distances are usually very helpful, working up to:
High X poles on short distances, e.g. a grid of X bounce X stride X stride XI (crosspole with level back bar, moving it up and out after a few goes). This will show the horse that he can snap up from short distances, and then open up and out.
Matt Ryan uses an exercise of making you trot to an upright in a really really slow trot and getting v deep on purpose, and gradually putting it up. Eventually you end up coming in to up to about 1.15m or more in this way (depends how athletic the horse is – the idea is to make them work really hard.) If they take off too early, you had too much trot and need to slow down even more. It’s a good exercise to familiarise both you and your horse with getting really deep, to train him to snap his knees up really neatly, and gives you confidence if you ever end up in a sticky situation XC eg sharp turn to a long route after a problem – you find yourself in trot one stride from a 1.20 solid fence.