As soon as your tour is over, conduct the drawing for any prizes you offered to readers and send them off. Be sure to include a nice personalized note to thank them for being a part of your tour. I know it's tempting to give yourself a day off, but take another day or two and finish strong. You'll be glad you did when it finally is all done and you can relax.
Make sure you use the contest to its full advantage.
Announce the winner(s) on your blog and the tour page. If your feed isn't too spammy, put it on your social media sites as well (use the hash tag). To keep the publicity going, invite the winner to send you a picture of them with their prize so you can share it on your blog and other social media sites.
These are all opportunities to get your book mentioned without obvious promotion. So take advantage.