Give him plenty of exercise.
Provide your dog with adequate walks and play time to use up his energy. Otherwise he will find something else to use up his energy: tearing up your house or chewing your shoes!

Keep training.
You can teach an old dog new tricks. Try to introduce a new command a week and practice the old ones with him too. You’ll both benefit from this. Your dog will understand what you want and it will mentally stimulate him, eventually tiring him out. AND you’ll have a well-behaved dog and quality one-on-one time.

Stop reinforcing bad behavior. 
If your dog is barking for attention, how do you respond? Do you yell at him to stop? You just reinforced his behavior by giving him attention. Think about what your dog is trying to accomplish hen he’s misbehaving and don’t allow him to be rewarded for it. Instead, give him an opportunity to succeed. For example, tell the begging dog to go to his place and lie down; give him a treat when he does.

Pay attention to your dog and their breed.
This goes hand-in-hand with #1. If you have a Border Collie who is terrorizing your home, but you give him a walk each mornign and night, you might think you’ve fulfilled the exercise requiremnet, right? Wrong. While a twice-daily walk might suffice for a breed like a Greyhound or Retriever, Border Collies were bred to work and need opportunities to run and “do a job.” A fast-paced game of fetch can do the trick.

Remember your dog’s age…he may be a typical teenager.
Like humans, dogs go through a rebellious “teenager” phase (from about 5 months to 18 months). During this time, they’ll often test their owners, seeing what they can get away with. Being firm and consistent with your training will help establish boundaries. And be patient! They’ll grow out of it.