What are some good methods for helping 18-month-olds learn about rules?

Teach and lead.: Divert and substitute. If a child is playing with something you don't want him to have, replace it with another object or toy that the child enjoys. This approach avoids a fight and does not place children in a situation where they'll say "no." teach and lead. Have as few rules as necessary and enforce them. Make rules for the child's safety. If a rule is broken, after a short, clear, and gentle explanation, immediately find a place for your child to sit alone for 1 minute. It is very important that a "time-out" comes right after a rule is broken. Make consequences as logical as possible. For example, if you don't stay in your car seat, the car doesn't go. If you throw your food, you don't get any more and may be hungry. Be consistent with discipline. Don't make threats that you cannot carry out. If you say you're going to do it, do it. Be warm and positive. Children like to please their parents. Give lots of praise and be enthusiastic. When children misbehave, stay calm and say "we can't do that. The rule is ________." then repeat the rule.

Everyone is differen: But being consistent and reasonable would be most important with the understanding that an 18-month old may not be able to follow too many rules and each child learns differently. Be patient.