There are some typical problems or frustrations that occur when cooking (and when dog training):
1. You never stop believing that the first recipe was ideal even if the results you get are not great or what you hoped for
2. You fail to practice sufficiently so that you can differentiate between a bad recipe and bad technique on your part (or lousy ingredients!)
3. Having decided your technique is at fault, you still fail to learn new ways of using the recipe
4. Having decided the recipe is at fault, you fail to actively seek out and practice new recipes
5. You blame the ingredients.
6. Having hit upon a successful recipe, you fail to remain open to the fact that there may be even better recipes or at the least, recipes that are better suited to some situations than your successful one may be
7. You keep focusing on the chemistry (an undeniable technicality) and fail to notice that it's a matter of feel, taste, appearance. Technically accurate and inspired are, well, rarely bedfellows.
8. Encountering setbacks or problems, you fail to look in all possible directions (technique, ingredients, the recipe itself, the chemistry of cooking which could even include subtle stuff like the shape of a bowl or the actual metal composition of the bowl - for example, egg white really do whip up with greater volume when beaten in a copper bowl), and then . . . consider that it may be an interaction of all possible elements.
9. All of the above
There's a reason many of us (including me) buy frozen pie crusts - it's easier! Unfortunately, it is also easier for a trainer to find a training "recipe" that works, stick with it, and be successful a good percentage of the time. It takes work and revision and introspection to keep pushing yourself to learn more, do things in new ways, discover ever more elegance in your approach.
Mastery of anything is a long, gradual process, but it's the journey that matters far more than the destination.
"Pie Crusts and Training Problems" by Suzanne Clothier