The House Rabbit Society offers the following:
"During the training time, do nothing but concentrate on the rabbit. Open the door to her home and let her (or them) come out when she chooses. You may offer toys or treats from your hand, but don’t interfere with her if she wants to explore. And watch her carefully throughout the time she is out of her cage. If the rabbit starts to chew on something you don’t want chewed, immediately offer him as many other things that are okay to chew on as you can. Block whatever he was chewing on so it ceases to be a temptation (block it well, so you aren’t simply challenging the rabbit to break through).