I think my Kiwi is very well behaved and friendly. I don't really ever discipline her in the traditional sense. I reward behavior I want and ignore behavior I don't want. I might say "no" if I don't like a particular behavior and it must stop immediately. Trust me, Yorkies hate to be ignored!
I think exercise is very important! We vary our walking schedule quite a bit. For example, yesterday we took a 45 minute walk. Today we are going out for 30 minutes, but that is because she has daycare. Two days a week she goes to daycare and comes home happy and exhausted. This has also helped a lot with socialization with other dogs.
Kiwi and I are taking obedience classes together, so we work on her skills in 10 minutes sessions at least twice a day. Hubby and I also spend lots of time during the day playing with her when we get the chance, she loves playing ball.
She is left alone maybe a couple hours a day. She does go to daycare when we will be gone at work/school for more than 4 hours.
Kiwi is on Solid Gold dog food. She eats it up and is at a perfect weight. She eats Zuke's for treats and especially likes the salmon flavor. She is not a vegetarian, but I am! I think dogs were made to eat meat and I am not sure how they could get all the nutrients they need without meat. I can eat a varied diet to get all the nutrients I need, but dogs can't eat all the different stuff that I can.