I took Joey to a tricks training class, and they suggested two new tricks a week. We would always practice the old tricks along with the new. The instructor said to be careful that they don't learn to do the whole routine on one take, in other words, some dogs will sit, roller over, crawl, beg, and pray, and you've only given them one command. The important thing is to keep training sessions short, two 5-10 minutes sessions a day is better than one long session. I use Joey's meals for training purposes because he was getting to chubby with all the extra treats. This site has some great advice with videos.
Dog Tricks! Shake, Crawl, Beg, Kiss, Roll Over, Bow, and more!