A couple of years ago, I attended a writing workshop at the Santa Barbara Mission featuring Darcy Pattison (www.darcypattison.livejournal.com) This was my first weekend writer's retreat ever and I went armed with my 200 pages of what I called a novel. There were many professionals in attendance (a bit intimidating!) but I was thrilled to be there. Every writing technique Darcy spoke about was new to me or at least new to my novel and I soaked up every word she said.
As soon as we arrived, and after a brief welcome session, Darcy had us analyzing our manuscripts. It started by highlighting areas of conflict, moved to plotting and then focusing on adding depth and layers to our novels. It was fantastic.
The one thing that stood out for me was a visual exercise called "Shrunken Manuscript". Prior to coming, she instructed everyone to shrink our novels by single spacing and printing in a small font. My novel ended up being about 30 pages long. With this reduced manuscript, she asked us to lay out our manuscripts on the floor, highlight different characters, look at chapter length, dialog and many other things. I focused on characters. I highlighted the main characters and secondary characters, laid the pages onto the floor and took note of what I saw.
For me, it was clear that some of my favorite characters were getting a raw deal. They showed up sporadically throughout the book. I thought about them for a while and decided to eliminate two of them (wasn't so sad to see Katie go but wanted to hang onto Ashleigh--but didn't). I revised my novel so that a stronger secondary character could take the place of the other two. It worked. Fewer characters and a stronger book.
I encourage you to check out Darcy's website. She has many revision tips that might work for you.