Describe problems and let children tell themselves what to do. If no decision is made, make the decision for them. Don't give a choice when one doesn't exist. Don't give unlimited choices. If you try, you will lose.
Children win if they engage parents in battle.
You can't force a child to eat but you can make certain he comes to the table hungry. Separate bedtime from sleeptime. Keep children in bed at bedtime but they can choose to sleep or not. Catch a child being good. What you notice you get more of.