You must have been bribing the dog all along rather than rewarding. If you've been showing the dog the treat before he does the trick, this teaches him what you're describing. Practice with a hungry dog. Get some special treats and put them a little away from you...on a counter or table. Bring your dog to you and try one trick. Make like you're going to have fun, a game, squeeky voice, playtime. Start out with his favorite trick. Does he like to shake? If he doesn't on his own, take hold of his paw and shake. Use your voice to praise and get a treat within 4 seconds. Do this several times. Once you're sure he knows the trick well, skip the reward here and there. But not altogether. Then go on to another skill and try that. Until the dog knows the skill and is doing it reliably with reward, don't try to eliminate the reward completely. Then vary the number of times he must perform in order to get the treat. Don't make a pattern....just every 3 or 5 times for a while, then, say, every other time for a few times, then every 4 times for a few....that sort of thing. Keep him guessing and trying. He'll try harder in order to get the treat. Then over time, you can space out the reward a little more. Eventually, he should be doing the skills for a little praise because he will have gotten into the habit of doing what you ask. Be sure to be a good leader, on top of this. He has to know that you make the rules and he follows them. Be consistant and follow through with commands. Make sure he reacts to your instigating things, not the other way around.