When riding, we are told to apply inside leg to outside rein. But what does that really mean? How do you actually apply it?
First, practice what the outside rein does. Here is what the outside rein does:
Next, get off the rail. The rail creates a false outside rein. When you come off the rail, it exposes if your horse drifts out the shoulder, collapses in the turns, and if he will actually go in a straight line.
Challenge yourself, stay off the rail about 3 meters at all times and test:
Straightness down the long side