This may seem like a given, but it is very easy to find yourself in the position of waffling on rules you have set. Likewise, it is equally problematic if you do not state every part of the rule in a clear and concise way.
Use positive reinforcement whenever possible.
For rules that don't seem to be followed using positive reinforcement, the parent must establish consequences for failure to comply. These must be realistic, match the nature of the infraction, and teach something if at all possible.
Repetition is an integral part of all learning and mastery. "If at first you don't succeed, try again." Decide how many times you will repeat a command before acting on it.
This is another given, but perhaps the most difficult to facilitate. Consistency in rules and consistency in following through with consequences are both extremely important. Children naturally look for loopholes such as trying your patience when you're tired, but these are the times consistency is most important and effective.
If two parents are involved, they must be in accord with what the rules are, what the consequences are, and what the procedures are for carrying out these consequences.
As always, who you are and how you act is the most potent guide and teacher for your child. Treat him/her with respect in all situations, and strive to manage his/her behavior with a calm attitude that comes from your understanding that self-control is ultimately necessary and good for your child.