In reviewing my own training work with the donkeys, I think my most common mistake is not splitting down the training into small enough bites. The way I can tell this is that although the donkeys seem to understand what I am asking, the resulting behaviour is sloppy.
For example, Ringo will stand in the centre of the barn aisle to be groomed, but feels he can wander away if he feels like it! Now that's bad! Sure, he'll come back when I ask, but he'll still feel okay about leaving! Same with leading ... he knows exactly how to respond to slight pressure from his lead rope now, but if he decides it's been too long between treats, he'll crowd me and cut me off. Shouldn't have to keep correcting - he knows the score.
These are some of the things I need to "clean up." Ditto with the jennys: excellent responses but lacking in duration and "exactness!" Alex always says" be a splitter, not a lumper." Although I think I AM breaking things down, the donkeys' behaviour tells me that it's not enough.
Patience and perserverance!