Here is a jump training workbook that covers every tip and insight I could cram into 7 pages. It contains a wealth of information about jump training. Here are a couple of exerpts - but check out the whole workbook!
Start by watching a dog take off for a jump.
This is a dog jumping in extension. A reasonable definition of this type of jump is that the dog takes off roughly 3 times the bar height away from the jump.
For example: at 20” height, they will take off about 5 feet before the jump.
In extension, a well-timed jump will follow a trajectory resulting in the dog landing about as far beyond the jump as they take off.
The highest part of the trajectory (apex) will occur over the top of the bar.
Video and go frame by frame!
Make sure your jump training takes into account all aspects of jumping:
Positive attitude toward jumping
Ability to scope ahead
Understanding of jump types (single bar, spreads...)
Understanding of type of jump (extended, collected)