I mentioned to Iris last night that I was working on my writing and she pointed me here as a source of useful stuff to do or not do in a fantasy story. Those articles actually work for quite a lot of writing outside of fantasy as well and are very interesting either way, especially if you consider some of the more well-known novels in terms of what limyaael has to say. Anyway, I've spent quite a while reading the articles and I'm still going (there are rather a lot), but good reading overall. Approximately half of them apply to me as mine I guess is technically urban fantasy, though with a lot less emphasis on the fantasy part (no dragons, no elves, no knightly orders, no old guys in big pointy hats carrying scrolls and staffs around, etc etc).
Also linked from somewhere in there is this little gem. We don't appreciate plot holes thank you very much. No, not even from you JKR.