Devote 5 to 10 (no more, make it fun) minutes a day, two to three times a day to specific training and you will see results. I suggest using one specific place in your house, a favorite training treat (we love Charlie Bears here), and a clicker. I can't speak highly enough about how effective clicker training is, as long as you do it the way it is intended. This website has a nice little dvd, and flash cards/ book that come with a clicker, try it you won't be dissapointed.
Karen Pryor Clickertraining | The Leader in Positive Reinforcement Training