Don't Call Your Characters Quirky

I have come to realize why I really hate people who describe their characters as "quirky": as a description, it actually describes nothing.

Consider what we mean when we call somebody quirky. In short, they have quirks. That means they have mannerisms which are odd to other people because they are not standard. Quirky people wear out of style or mismatched clothing; they have a verbal tic like pronouncing words oddly or avoiding certain words or phrases; they have a physical compulsion like an eye twitch or a half smile or they snap their fingers to accentuate a point.

All of these things are weird to us. But they aren't weird to the person that does them. Unless they have a disorder which causes their affectations, they are choosing to wear certain clothes or snap their fingers. These decisions are expressions of their personal beliefs or upbringings, but they are not themselves characterization.

If you have a story and your main character "snaps his fingers to emphasize words", then you have a very weak story. I still know nothing whatsoever about this person. You might as well say you wrote a story about "a guy who wears pants". Unless your story is about why your character snaps his fingers, then it is completely irrelevant.

When you have a "quirky" character, you are trying to pass of their habits as characterization. But if you do that, they will always fall flat.

I don't necessarily mind starting the character-making process with a quirk. I certainly can see it as a starting point with a lot of potential for creativity. But it is just that: a starting point. If you can't go deeper than describing their looks or tics, then you simply don't know your character, and it'll be impossible to get other people to care about them.