When to Potty Train

Our daughter is 20 months old and we have spent the last 3 weeks trying to potty train. She caught on to holding it pretty quickly, but never seemed to get the idea of telling me she needed to pee. We tried the timer method and that was wearing me out, but we weren't having too many accidents. The we tried the 3 day method and LG seemed to get the idea of keeping her panties dry and holding it, but still wouldn't tell me she needed to go.

Frustration is starting to set in, so we decided to postpone things and try again in a few months. What is your experience in starting potty training? What is the ideal age and methods that work for you?