My only experience in training is my own Chi x (who is not naturally biddable, she seems to be one of those 'clever' dogs that has a mind of her own) and my parents' gorgeous Stafford girl. She is sweet, happy and loves training while she is having fun - her rewards are usually food rewards or toys with lots of praise thrown in. But once she decides she's had enough, I can forget about it. My challenge is to keep sessions short enough and varied enough to not bump into this. Which sometimes I do quite well and other times I fail miserably at. It's so much harder to stop something when it's going well.
This sweet girl, who I have so much fun training, is the same dog that will stubbornly sit on the top of the stairs and not respond to my 'excuse me' about 80% of the time (I love how I've got a 'success' rate on failure for this exercise lol). She likes to just stop in the middle of paths and make people go around her... she's done this forever and we were too lazy to figure out a way around the behaviour (pun intended) and in the end we decided it was just easier to walk around her.
Plus, now she's a senior dog, she deserves lots more privileges (read - now we can justify all the little things that we didn't train particularly well from day 1
). But hey, we live with it - let's face it, it's a rather mild 'problem' to have, and I wouldn't change her for the world. Grace is awesome.
Abby also needs very short sessions, and her arousal levels need to be up, up, up and maintained for that short period of time. And then she is awesome. If I get sloppy, unclear or come across as as much fun as a limp dishcloth, then forget it. Training does not come naturally to me and I have to be fairly disciplined with myself to remember what my plan is or remember what to do if such and such happens, but I find if nothing else that if I'm genuinely having fun... my sessions turn out ok.