There really isn't any one way to do things. There are just too many variables involved which can change things. Some guys take 1 slin injection...some take 2 within close proximity to each other, with dose being determined by nutrient intake-availability.
As long as you understand the reason for using insulin, which is to enhance the rate and extent of nutrient transport into muscle tissue, you can construct an effective program based on your pown preferences, finances, and goals.
Research has shown us that mucle protein synthesis and nutrient delivery is at its peak both during and right after a training session. Therefore, it makes sense to supply the body with the nutrients needed to maximize protein synthesis and glycogen replenishment at this time. Injection timing, injection dosage, and the number of injections all depend on when you eat, the type of food you eat, and the amount of food you eat. As long as an optimal amount of carbs & protein are present during the training window and you are using a dose of insulin capale of transporting those nutrients into the muscle cells, recovery & growth will be maximized, at least in terms of slin use.
I can't provide an "ideal" program for everyone, which is why I am not listing one. There are just too many variables which can change things. For example, some guys have a very tough time training with even small amounts of food in their stomach, especially on leg or back day. Obviously, under these circumstances, food intake will be very light in the pre and/or intra training meal, with some guys consuming nothing but various amino acids and other low-volume ingredients, while the majority of their carbs will be consumed immediately after training. Someone in this situation would not be injecting very much insulin, if any, right before training. In this case, insulin would be used right after training.
Other guys don't have this prolem and are able to consume shake-based carbs or even whole-food carbs without issue. This could completely change their injection timing and even their dosages.
The original program I provided was designed to straddle the line between effectivness and safety, which could be used by any beginner without short or long-term harm. It accomplished the objective of maximizing protein synthesis, while simultaneously replenishing/maintaining glycogen stores. In terms of food qauntity and insulin dosage, my selections were based on the needs of the typical mid-level BB'r. It is impossible to have a single insulin dose or dietary recommendation that is ideal for everyone because no one person has the same needs. Therefore, I selected an insulin dose and amount of food which would be suitable for a typical intermediate BB'r just starting to use insulin.