This is probably the best thread I've found... As a newly started solo business, I've already begun changing the way I do things simply due to the information in this thread.
I don't know that I have been in business yet to have 3 things, but I would def. say that I wished I'd never have low-balled quotes on lawns... and don't take on lawns that are too big for your equipment. I've had to drop a client simply because I could cut three yards in the time it took me to cut his.
I haven't been able to get away from the bi-weekly (or as it needs it) accounts. But I have made one client that really seems to care about their yard, so maybe they are my key to others.