It's easy to resort to yelling when you are disciplining your child, but this may just teach him to raise his voice. Instead, find alternatives. This will make a quieter home -- something every parent wants -- and teach your child that yelling isn't the answer. Using a calmer voice can also open the door to finding different parenting strategies that will keep you and your children motivated to work together.
Redirect your child by giving him a more appropriate task that he might like. For example, if he grabs a toy from another child, give your child a different toy to play with. If another task isn't appropriate, you can try removing him from the situation and putting him in a new one. If he is arguing with children on the slide, try moving him to the swings to see if that works better. Redirection works especially well with toddlers.
Make eye contact with your child and tell him you understand why he's upset but that she needs to change his behavior. For example, say something like "I know you want that toy, but it's not your turn. Play with this toy until it's your turn." This makes him feel like you understand him and that he is not going to miss out.
Set reasonable expectations. Write down the rules that cannot be broken. For some families this might include cursing and hitting. Set concrete consequences for these rules so children always know what to expect. Be consistent. Try other methods, like redirection, for other behavior that is undesirable.
Praise or reward good behavior. Your child is more likely to act appropriately when he receives positive attention for a behavior. If his misbehavior is not harmful, ignore it, while providing positive attention for good behavior, recommends PBS Parents. Over time the desirable behaviors will become ingrained and there will be less undesirable behavior.
Model the behavior you want to see in your child. Of all the parenting techniques, this is the one that will be the most effective in the long-run. If you don't want your child to yell, don't yell. If you don't want him to hit, don't spank. Modeling good behavior is the best way to ingrain good behavior in your child. Nobody's perfect, but aim to consistently set a good example for your child.