There are so many things to keep in mind when writing a novel. You have to have interesting plotting, good writing, and well-developed characters, and you have to make sure there are no continuity errors introduced during your revisions.
But are you keeping in mind whether your manuscript is an appropriate length? Of course, ultimately the appropriate length is the one that lets you tell your story effectively, but there are word length conventions for any given genre, and if you fall outside them there generally needs to be a very good reason for it. I tend to prefer books between 80k and 100k words. On average 30-40% of the queries I receive are for works that are much longer than that, many reaching 120k or more, and typically these manuscripts are in need of significantly more editing and revision. Recently I’ve also had a rash of queries that are far too short, about 40k-50k words. There are exceptions, even for first novels, and for hugely successful authors there is much more latitude to go in either direction, but it is best to know what your range should be and if you don’t fall into it, to think very carefully about whether there is either more you can cut or more that needs to be developed.
If you’re curious as to the recommended word counts for your genre, Chuck Sambuchino has a “definitive” post on word count for novels and children’s books at the Writer’s Digest Guide to Literary Agents blog.
