In general, I do find the problem Lars mentioned: many Wikipedia articles exist "in isolation" and are poor at discussing broader context. I try and stop and think, "What is the reader likely to want to know?" It's hard to think from the point of view of the reader, rather than that of the writer, but trying is worthwhile.
I also try and send people I know to articles, and have them give me feedback. Sometimes others can see what a contributor cannot.
-Matt