Do they work for your child?
My youngest will be 3 next month and I've found that for "him", time out has been very effective. He hates to have to sit in his time out spot and so far, if he's not listening to me, just the words "time out" is enough to get his attention. However for his 3 older siblings, time out was never much of an incentive and we just sort of muddled through until they were old enough to learn about loss of privileges. My oldest was the most difficult because she has special needs and has a hard time connecting consequences to actions. She's learned it over time...just took longer than the others.