I don't know if anyone else had this same experience but our shitzu didn't need to be trained at all. She automatically understood do's and don'ts. Only a few times she got out of line but nothing that needed training for. The nicest and most rewarding pet I have encountered.
You are most likely very good at keeping a consistent attitude towards things. Dogs can pick up on human emotions very well and will often know just based on your body language if you do or don't like something that they have done. for Some dogs simply knowing their person does not like something is all the training they need. Some dogs just don't care enough initially if you don't like something. I have one dog who is an opportunist. She won't do anything bad If there is a person around(she knows right from wrong). If there is no one near by, she will steal food off the counters and destroy everything. she dose not care about the long term trouble she might get into.