At first for me it was about getting through the day - just one more day. Then when I got to six weeks I thought I'd get to 12. Then to 6months, then after that I think I stopped worrying and just let her go. She weaned herself at nearly 16months.
With DS well he's just gone from 3 to 8 (!!!!) feeds a day so he's showing no sign of slowing, and TBH I'm not really fussed.

I know a few girls who have said that they were only going to 12months and then on the day of their child's birthdays they started with milk and no BFs. I think that's a terrible way to end it, but that's just MO.
I think active and positive encouragement has a lot to do with it too. I had no ideals before I had DD and when i found it tough got lots of positive encouragement here, whereas the only positive encouragement IRL was DH.