one trick is to keep having more babies and then you never have to worry about it!
but truthfully, having just had my third baby in 3 years, I am now really focusing hard on it. My second child did not breast feed and now that I am breastfeeding my 3rd, it makes such a difference, i found it much easier to lose weight.
But I have found that it is not just losing the weight that is the problem but retoning my body. I did Yoga throughout my pregnancy so that helped a bit but a friend of mine did Pilates and her stomach just popped back into shape after a few weeks. So I am going to try that now as apparently it really focuses on the stomach muscles.
If you have time and money, get a personal trainer once or twice a week as it is a great motivation. I dont know about you, but after a full day looking after the kids, I never have the energy to go to the gym!
good luck