The fact that you need to discipline your children is not an open invitation to treat them with a lack of respect or decency. It also doesn't mean that you take on the role of Czar with your children as the peasant slaves.
Letting kids be kids
Kids will be kids and should be allowed to make mistakes, make messes, and get mad and upset. You can't expect miracles from people who may not be as old as your favorite suit. Kids are awkward at times, spilling and dropping stuff, knocking things over, and generally doing things that are goofy. They typically are not malicious or evil. Be careful that you neither punish typical kid behavior nor give them unrealistic expectations that they can never meet.
Don't make words less meaningful by using them again and again
Instead of always saying "No" or "Stop," offer alternatives to whatever your children are starting to do. When you see your children starting to color on the walls, say: "Don't color on the walls. Here is a piece of paper. We can color on the paper instead." If you're always yelling out "No," "Stop," "Don't," "Quit," or "Help me, my children are taking over," your words lose their effectiveness after a while.
You don't always have to win
Discipline shouldn't be a series of wins and losses in an on-going battle between you and your children. Discipline sometimes can leave room for compromise between you and your children as long as you get your point across.
It isn't important that you always win the clothing-selection war, for example. Clothing may be one of the first areas in which you find yourself coming to a mutual compromise with a child. Your goal is getting your child dressed, but your child may want to exert her independence by helping to choose the clothing. This is a situation in which you compromise by coming up with an outfit that you both can live with.
Parents tend to think that whenever they don't always get their way, they're letting their child run over them. Think about the getting-dressed scenario. Your goal is getting clothes on your child. Does it really matter whether your child wears the blue button-down oxford shirt or the Mario Brothers T-shirt just as long as your kid gets dressed? No, of course it doesn't.
Handling situations with gentle guidance
Getting your children to do something often is just as easy as coaxing them not to do something. Likewise, being gentle about getting them to do it is just as easy as yelling and screaming at them. Don't forget that your goal in disciplining your child is to teach. Your children are more open to listening to and hearing you when you express what you want to say in a kind and gentle manner. Don't be surprised, however, if you can't always accomplish that. You may find yourself quickly losing your temper and yelling when you walk into a room to find mud all over your white carpet. The goal here is to at least try.
Using enthusiasm to guide your children
If you're trying to get your children to do something they don't necessarily want to do, approach the situation with great enthusiasm, making it sound like fun. When you make the process of getting your kids' shoes on them fun and like a game, your children will think doing it is fun, and then maybe they'll forget to scream, kick, and throw the shoes across the room.
Don't harass your children
You always need to have faith that your children are going to do what's right. You can't sit waiting, like a cat perched in front of a mouse's hole, for your children to do something wrong so that you can pounce on your prey. Neither should you fall into the trap of scolding your children before anything happens or in anticipation that something may happen. That is just nasty behavior on your part and needs to be avoided.