try putting the treats on the counter and have her do a sit, then get the treat off the counter instead of having it in your hand. Then make him do a sit and a down before rewarding. Then 2 sits and 2 downs then rewarding. Slowly wean him off the treats. But dont brake them off completely because hes been taught using positive reinforcment. Basically to him you'll end up being like a slot machine. He'll continue to give you his all because he never knows when hes gonna get it. Dont go to long without rewarding though or he'll give up on you. As far as tricks go, there are plenty you could try. Fetch, take it/drop it, shake - our dog is only permitted to go through doors on command (which prevents the dog from running out through the door accidentally) Most of these have hand signals, so I can give him just the verbal cue, just the hand signal, or both together, depending on the situation. We also hung a bell on a string by the door and we are trying to get him to ring the bell when he wants out . Its actually working pretty well. Good luck.

The most important thing in dog training is consistency and patience. You cannot let your dog get away with bad behaviour because you are tired or do not have the time. 

Also, with dogs there is usually a reason for bad behaviour such as barking, digging, or chewing. For barking, work out what exactly it is that they are barking at and try and eliminate it. And for the other two make sure your dog is not bored and it is being stimulated enough every day. Regular walks, everyday makes dogs very trainable!