All dogs chew and most of them will chew on something they're not supposed to from time to time. The best way to avoid this is to keep your dog crated when you can't give him your full attention.
Disciplining a dog after he's done chewing on something is useless. If he chews your shoe, comes to you and gets yelled at, all he'll understand is that he gets yelled at when he comes to you. And, no, showing him the shoe and yelling at him won't work either. He'll look very sorry but will have no idea why you're so upset with his new chew toy. Unless you catch him in the act of doing what you don't want, yelling will not train him and may make him think you're not really the kind of person he'd like to come to.
When you catch your dog chewing on something he's not supposed to, tell him "no" but also make sure you substitute the "wrong" item for something he is allowed to chew on. Here's how it works:
- Catch him in the act of chewing your shoe.
- Treat him like he's the worst dog in the world for no more than five seconds.
- Give him something he's allowed to chew on.
- Immediately praise him like he won the Nobel price in dogonomics.
From your dog's point of view there's no difference between a leather shoe and rawhide. It takes time to figure out what he's allowed to have. Not letting him loose in the house when you can't watch him will go a long way to making sure he's learning these things right the first time.