Well, Maeglin did a better post than mine, but since I’ve written all this, I’ll post it anyway.
First, bear in mind that artists are trying to please someone. This is because artists, like everyone, have to eat, and artists, like everyone, crave approval. So there’s nothing terribly mystical going on in the motivations of artists.
Second, art is almost always within the bounds of what the common viewer/listener/reader can comprehend. Basically, the artist goes for a mix of the expected and the unexpected. If too much is in the expected category, it’s boring. If too much is unexpected, it’s alien. Neither gets an audience. If something is wholly alien to you, it’s because you’re missing intermediate steps that led up to it. Find out what those are, have a look, and then see if the alien thing makes more sense.
Third, art afficionados have a natural tendency toward being pains in the ass. They confuse “I (don’t) like it” with “It’s (not) good.” At the lowest level, you get “Beavis and Butthead” assessments: This is cool, that sucks. Go to youtube, search for your favorite guitar god, and then read the comments. The world is awash in snobs. Screw 'em.
Then you get to a higher level where someone is actually eloquent about explaining why he does or doesn’t like something. Enough people saying the same thing apparently makes it true, at least to the people who pay attention to such things. That doesn’t mean you have to fall for it, though.
So, seek out good critics of an art form, by which I mean, people who are dedicated to expanding one’s knowledge of the art form in question. Avoid people who are only in the business of passing judgement; they are singularly unhelpful.
Fourth (and really just coming back to the first point), people seem to like sacred cows. Ignore that. Before Michaelangelo and Beethoven and Shakespeare were sacred cows, they were just artists, trying to please someone. Keep that in mind.