This is a good tutorial.
However I would like to note that when it comes to hyenas, I always use sickle tail. Hyena tails may not be curly, but they are also not as nearly as long as wolf/cat/thin tails. The sickle tail is the closest to the possible proportions.
Also, with horses. Horses have incredibly long muzzles. Even the shortest muzzled horses have muzzles much longer than any wolf or canid. But you said to make the muzzle length short as it could go??? I find horses look most realistic with the muzzle size as long as could be.
However I agree with everything else, and I bet people will find this helpful.