(Caveat: I'm not a specialist on this topic. In fact, so far I'm a total failure. But this is my opinion on what I should be doing!)
I am increasingly convinced that discipline is a key to life balance. No, not self-discipline - although that's good too - disciplining your children.
Don't get me wrong, I'm not talking about training them to a whistle, like in the early scenes of The Sound of Music. I'm talking about teaching your children to be polite and obedient, for their own safety and for your sanity.
Teaching children to be obedient doesn't mean they turn into automatons. You're not an evil parent breaking the spirit of your child just because you expect to be listened to and cheerfully and promptly obeyed. Children can still ask "why?", and you should give them a reason for your request. Children should have the opportunity to discuss their objections and desires, and to change your mind if warranted. But once you've stated your reasons, and their serious arguments have been dealt with, you should not allow the whining and the delaying to continue. Think of it this way: your time and theirs is too valuable to be taken up in an endless whine of "But please, Mommy? Please, please, please?"
Discipline sucks in the short-term, because it involves a fight that can be avoided by just giving in. In the long-run, taking the time to install proper discipline will give you more and better time to spend with your child, running around outside, doing art projects, cooking together, reading books, talking about things that matter to your kid. And, frankly, when you say to your kid "Don't run across the street without holding my hand," they sure as hell should listen to you. If you haven't instilled in them a healthy respect for your commands, you aren't doing your job as a parent.
Obviously, kids don't always listen to us, no matter what we say or do. If I see you in the grocery store and your kid is acting like a brat, I'm not going to judge you. I've had enough melt-downs of my own in public (and so have the kids - ha!)
I'm not an expert on discipline, by any means. I'm only starting on that journey myself. Bunny turned four this past summer. She's been taught some basics of discipline from a very young age (obey Mommy on certain safety rules, and do age-appropriate tasks for herself). She's getting to an age where we can demand more, and start working on her attitude. I won't say her whining, crying, complaining days are behind her, but we're trying very hard to teach her prompt and cheerful compliance to important rules and requests. I'm sure it'll only take her another twenty years or so to master it.