Be The Alpha Dog

To successfully train your dog, you must be the leader of your pack, or at least rank above him. Always be firm and consistent with your dog, as this will show him that he can't get away with everything, even if he really is the cutest thing alive. If you fear that you may already be underneath your dog in rank, don't concede to defeat and continue to let your dog hog the blankets at night - toss him off the bed. While it may seem mean, it's a good idea to show your dog who's boss by pulling rank on him occasionally. Make him get up from the couch so you could sit in his place, and eat your meal before feeding him his, even if he's drooling a lake by your feet. Don't act scared if your dog growls at you when you ask him to do things - just snarl back without touching him and stand your ground. Continue prodding him to obey you until he does.

As for the non-puppy owners, you've probably heard the saying "you can't teach an old dog new tricks." Well, whoever made up that line was either a very successful liar or someone who lacked the patience to really communicate with his/her dog. While it's true that old dogs don't come with clean slates, they will obey your foreign commands if you make it worth their while to do so. So don't fall for that fallacy.

You should NEVER yell at or hit your dog, no matter how frustrating training can get. Going ballistic only teaches your dog to be nervous around you and fear you, making it hard for him to concentrate on what it is you want him to learn. Habits, good and bad, are formed when an action is repeated over and over again with consistency. So during the process of training your pooch, don't give up the routine until he's got it. And even after your dog has mastered the following tricks, test him on them from time to time to make sure that he's still got it.
Remember: Repetition with rewards will reap the right actions/behavior.