What I Learned at Clarion
(As suggested by Jim Kelly.)
It doesn’t matter how cool and awesome your ideas are if you can’t present them in a clear and comprehensible fashion.
Being clever for the sake of being clever isn’t a good idea if the clever bits interfere with the story you’re trying to tell.
Trying to think about “plot” and “character” (and even setting!) in isolation isn’t much good. They rely on complex interactions and are inextricably entwined, and you can’t change one without affecting the other(s). For example, once you really know a character, and understand what they’d do in a given situation, the working-out of the plot largely takes care of itself.
One man’s brilliance is another man’s bullcrap. That is: what one reader finds sweet another might find saccharine; what one finds wonderfully transgressive another might find merely disgusting; what one finds charming another might find twee. Even a technically accomplished story won’t please everyone.
Try to write about stuff that matters to you, and embrace your weirdness, your idiosyncracies, and your obsessions. That’s where your individual voice comes from.
(I could have written a list with a lot more “Don’t drink that much tequila,” and “During watergun fights, avoid hiding in patches of poison ivy,” and “Fred means you no harm — probably,” but I figured I’d focus on the writing stuff.)