You know, I can really relate to what you're talking about. I used to draw frames because that's what people tell you you're supposed to do. My stuff always came out looking like crud when I did that though.
One day I said TO HECK WITH IT! And decided to go by shapes of dark and light rather than stupid ovals and lines (my appologies to the humble oval btw).
But it's ok... turns out that skipping the step for people like us can work too:
http://img.photobucket.com/albums/v113/Mari-3/rabutempcopy.jpghttp://img.photobucket.com/albums/v113/Mari-3/CC2copy.jpgOften I don't draw sketches at all, and if I do it looks something like this:
http://img.photobucket.com/albums/v113/Mari-3/SZTpromo2copy.jpgfor something like:
http://img.photobucket.com/albums/v113/Mari-3/Fight_from_Shizentai.jpgMy advice is to do whatever works for you.