There are some jobs that are only done by accredited professionals. And then there are most jobs, jobs that some people do for fun, now and then, perhaps in front of the bathroom mirror.
It’s difficult to find your footing when you’re a logo designer, a comedian or a project manager. Because these are gigs many people think they can do, at least a little bit. If you’re doing one of these non-dentist jobs, the best approach is to be extraordinarily good at it. So much better than an amateur, that there’s really no room for discussion. You don’t have to justify yourself. Your work justifies you. The alternative is to simply whine about the fact that everyone thinks that they can do what you do. The thing is, it might be true. – Seth Godin..