QUESTION: My novel is way too long. Someone suggested I cut four lines off every page instead of trying to cut whole chapters, etc.
Anyone who can do that needs to work on their writing skills because they are writing weak, bloated prose.
There are other ways to cut length.
From working with writers over the years, I'd say that the primary thing most writers need to cut is writer information. We sometimes do our thinking on the page before we write down what the reader needs to see, and we fail to cut that out.
Writers also tend toward too much introspection. If all a character is doing in a scene is thinking about other things, get rid of that scene and insert that information into dialogue.
The great Phyllis Whitney once said that the only reason a character should be folding laundry and thinking is so an ax murderer can sneak up on her, and the reader knows this through subtle clues.
There's also the rule of three. If a scene doesn't contain at least one or two plot points (information or events which move the plot forward), and one or two character points (important character information) so that you have at least three points total, then it should be tossed, and whatever points included in that scene should be added to another scene.
For major cuts, you can also consolidate several secondary characters into one character, or a subplot can be simplified or removed if it doesn't influence the major plot or the influence can be moved to another subplot.
Here are a series of blogs on book promotion from agent and former book publicist, Colleen Lindsay.