Training by objective is the key of animal training. Do not attempt to train your animal on a complex behavior. If training is too difficult, your animal may end up giving up in training prematurely.
In training complex behavior, you need to break down into smaller bit and pieces. This is what you call back-chaining. Allowing your animal to understand the final behavior will increase your chances of achieving the final behavior. Always remember to work on positive reinforcement, your animal work better in reward-base training techniques.
On a different note, I am in a dilemma when it comes to trialing. My personal believe is to allow my students take on the Course Designs on their own interruption and understanding of their animal. What's best for them as a team? However, in recent time, I understood that some of my students are actually thinking that I should coach them during or after their walk-through. And guess what? We are seeing positive results.
I think it might not be a problem if I allow my students to understanding the course designs and then offer some practical insights on how I approach these course if I'm running their animals.
Anyway, I am always searching for the better approaches and if the new approach is effect, I shall use it to bring out what's best in the team!
Happy Training! Have Fun and Stay Positive!