Ah, the Internet is a wonderful thing, isn't it? I was just reading someone talk about how real improvisation experts don't really like Thank God You're Here (the alleged improv show from David Grier and David Foley) which led to a link from an improvisation expert explaining why he didn't like the show which led to a link on How To Be A Better Improviser.
Now why would I bring that up here on my blog about comic books?
Because the "rules" for improvisation comedy denoted in that last link are ALSO excellent rules for writing in general, and comic books in particular! The basic idea behind/summation of all of these improv rules is to get the ball rolling quickly so that your audience knows what's going on and can follow along as the scene grows organically. Which is exactly what comic book writers should be doing as well!
If you've read a bad comic book -- and I'm sure you have -- what types of problems did it suffer from? Aside from possible problems with the artwork end of things, it was likely either because A) the story, or at least parts of it, didn't make sense; B) characters were not identified well or didn't serve a useful purpose in the story; and/or C) nothing significant happened. Go back and pull out the worst issue in your collection, and see if it wouldn't have been immensely helped if the author had followed those rules of improv.
And, of course, the over-arching rule of everything is what I've been tacitly implying: don't overly compartmentalize your learning. Don't focus on writing comic books; take everything you've ever learned and apply it to your writing in general. Being able to do that is what separates an Alan Moore from... well, anyone else who doesn't write that well!