A great tip, to save potential, dont whip or drive forward until your stamina runs out. Try and save your horse to its max.

The better the horse and ability wise, the more potential you will gain by comfortably riding the horse. This is why good horses win races. They gain more potential because they have more ability.

To practise, go to training and ride a class C horse then ride Dancing Blaze and see the difference. Hopefully this will raise your confidence a bit:D