Having children is one of the best things one can experience. However, this does not come for free. Most parent experience a lot of stress caused by the children and the responsibility for them. Since the children are born we rarely have more than a week in a row without worrying about our kids. Unless you really want to go nuts, it is an imperative to learn how to cope with such situation - fast.
There are a few effective ways of keeping your temper down and you should do your best to learn them as soon as possible. First, in case of coming trouble take a few deep breaths and close your eyes for a second. It will cause your muscles to relax and stress level will temporarily decrease. Then, remember that you can always walk away for a minute when the stress becomes unbearable. It is not running away - it is just taking a short break before getting back to your duties.
Speak your mind, even if it hurts. If you decide to let the situation spin out of control because you ignored the first signs of a problem, you're the only one to blame. You can't count on your children that they know what makes you stressed or what you want them to do unless you tell them. Avoid confrontation and you will end extremely stressed about more and more things until you won't be able to hide it anymore and explode, possibly ruining the relationships you might have with your children.
Another thing is that you have to remain in control of a situation. Never let it follow its own course if you feel it's not going to end well. If your kids are going to do something improper, bad or simply stupid, be the first to tell them that. If you can't cope with the problem otherwise, use everything you have in your power (including grounding and similar punishments) to keep your children from doing things you don't accept. Explain your reasons to them, but never let them make big mistakes - it is the shortest way for a parent to suffer a nervous breakdown.
Even the least important sources of stress can change your situation from happiness to horror and ruin your health in a matter of a few years. Here's how to avoid it: make sure that the situation in your family remains under control, your children know about the rules and the reasons for following them, you never get angry in front of children and you discuss problems with them rather than solve them singlehandedly.