The first approach is ignoring the problem, thinking and hoping that over time it will just magically go away. There are many behavior problems that are written off as 'normal puppy behaviors' such as fear, anxiety, resource guarding, separation anxiety, just to name a few. It is not uncommon for people to think that these are normal puppy behaviors and over time the puppy will just outgrow them. When an adult dog is displaying these behaviors people will often just learn to live with it as they feel there is probably nothing that can be done so what's the point in seeking help.
The second approach is to immeidatley jump into assualt mode which often results in resorting to using harsh and punitive methods to try to resolve the problem. People will run to the local Pet Store and arm themselves with an arsenal of equipment guaranteed to make their dog see the error of their ways. This can feel very empowering, especially if you have been feeling helpless and frustrated. The problem is, it's almost always destined to fail and the one who suffers the most is the dog.
The best approach is, trying to understand the underlying problem or what may be driving the behavior. When a dog is displaying an undesirable behavior there is usually more to it than meets the eye. If they are immediately labeled as difficult, dominant, stubborn, or worse, you've labeled the dog before you even try to understand the problem. Behavior is complex and changing all the time, it's influenced by many things, you often have to dig deeper to solve a problem.
Whether your dog is peeing on the carpet or eating foreign objects, it's serious and needs to be addressed. There are some behavior problems that are linked to an underlying medical problem. Don't think ignoring it or a 'firm hand' are the answer, try a little understanding first.