Any new skill you want to teach your horse is just, really, simple behaviours performed on cue, or complex chains of behaviour that build towards an end behaviour. Trainers who teach horses new behaviours using shaping are less likely to cause horses behavioural injuries, while also being more likely to quickly achieve their training goals.
Once you and your horse understand the concept, shaping new behaviours is fast, and fun, for you and your horse. This approach also builds your horse's try: their willingness to engage in training and offer new behaviours that earn reinforcement.
Once you get comfortable with shaping, you likely won't need to write out a shaping plan for every behaviour you want to teach. But it is helpful to do in the beginning, and later if you run into problems.