Give advance notice. At least 10 minutes before bedtime, say something like: "In a little while it will be time to go upstairs, brush your teeth, and put your pajamas on." That gives your child a chance to finish up whatever she's doing and mentally prepare for the evening ritual.
Follow the plan. Once you design a routine, do things in the same general order each night. Consistency is very comforting to kids at this age. So is knowledge: Teach the routine with a song like "This is the way we brush our teeth, brush our teeth..." or make a chart from drawings or cutouts.
Save the best part for last. Do the fun activity -- reading a book together, chatting about the day, playing a quiet game, listening to music -- when your child is safely tucked into bed. That way, it can motivate him to get the boring tasks done. But make sure he understands your special activity has a time limit -- and warn him when it's almost up: "We have two more pages, and then it's lights out."
Allow time for last-minute requests, and then leave the room. If you make a habit of sitting in a chair or lying next to your child until she falls asleep, she'll become dependent upon your presence for sleeping -- and you'll both be trapped. While it's your responsibility to put your child to bed, it is your child's responsibility to learn how to put herself to sleep. If she needs more time to relax, it's perfectly okay to turn on a soothing music or story tape, give her a flashlight or special stuffed animal, plug in a night-light, or provide whatever other reasonable props she thinks would help -- but it's not okay to act as her wake/sleep transition object. The sooner you break such habits, the better for both of you.
Tell your child you'll return to check on him. For example, say, "I'll come back in a little while to make sure you're asleep." That way, he'll be less likely to stay awake worrying that he's all alone or that you've abandoned him.