When training the younger horse in xc skills it is important that you educate them to read two or three fences at once. It is essential for the less experienced rider to learn also to give horses an extra ‘thinking’ stride when there is more than one fence to negotiate.
To coach this I will often use off-set brushes or rails across on a diagonal line with 23ft between middle to middle. Walking the rider through the exercise will benefit initially as it trains them to get a feel for the turn on the approach. I will always try to insist that riders always find at least three straight strides in front of a fence as it often takes a horse three strides to lock on, work out what it is they have to jump and feel their take off place.
To start with I would use rails and keep them quite small till the confidence and understanding is established. I would always educate the rider to have a focal point for this exercise as I feel if the rider holds a line with their eye then the horse will also stay straight. Sometimes to get the rider to recognise when the horse has ‘locked on’ I will get them to acknowledge it.