I think my biggest weakness is dialogue, especially in my own writing. I can just never seem to make a good conversation that doesn't look staged or choppy. Sure, I can pick out choppy dialogue (almost always it is in my own work) but my issue is correcting it. I also frequently resent the fact that I'm a "'Murican". I just think American English is relatively terribly spoken, and I devoutely avoid slang and try my hardest to imagine myself saying whatever I write in a British accent, mostly to affect my writing, but partially to make myself feel better.