I first read something similar to this in the "Now What?" stages of the NaNoWriMo blog. However I've tweaked it a lot and so it's different from what first gave me the idea. I'm not a huge fan of editing--but this method makes me actually look forward to it.
It's broken up into simple steps with different colors for each one. I use colored pens and underline or circle sections, using a pencil or a regular black pen to write notes in the margins or on sticky notes that I attach to the paper. But if you're a highlighter kind of person, you could definitely use that instead, and of course feel free to switch up the colors. I just use what I have on hand, and have a personal system for what color goes to what editing step, but you can change it. :)
Step One: If you've just finished your book, set it aside for at least a week. I like to go about a month. This allows you to look at your novel with fresh eyes. If you haven't written in it for a while, you're going to print out your book (I do it on single side of the paper to offer more space to write notes on the backs). Then read through the whole thing, if you can in one sitting. If not, just as soon as possible. Don't try editing at all during this time, unless you printed out the copy with sections you already planned on deleting. For instance, if you happened to write it during NaNoWriMo and you put in a monolouge about the weather just to add words, knowing you'd take it out later for publishing-- cross through those now with a red pen. Also, if you notice a character that wanders around with no purpose, give a quick note about them as well. Other than those kinds of things though, refrain from editing! This stage is to just get a feel for your book.
Step Two: By this time, you probably have an idea of what you got right and what you got wrong in your draft. But like I said, don't randomly attack the thing with scribbled-y red ink. If you go back to the beginning, grab an aqua pen. You're going to read through the book again, this time focusing on emotions/tension/reactions etc. What places make you laugh? cry? feel suspense? Is there no emotions when there should be? Or maybe the wrong ones? Did your character act or say something out their norm? Are they behaving too melodramatic? Too stoic? This is the time to go through and mark with your aqua pen all the feels (or where there should be some, lol). Make sure that you're following what your character's responses would be, not what yours would be.
Step Three: Grab an orange pen, and this time you're going to read through it again, looking for places where you're bored, confused, there's plot holes, or inconsistencies. If you need to fact-check various things in your book, this is the time to put a little asterisk or something beside those things to check later.
Step Four: Stop now and reevaluate. You will probably want to change some more major things here. After this step, I realized I needed to rewrite the entire ending for Jonas and Olivia. If you have huge scenes that need to be changed which will take the book in an entirely different direction, or you need to get rid of or fix a character you noticed was there for no good reason (noticed in Step One) go ahead and do that now. To eliminate the need of having to reprint everything again, just write these thing on the backs of the pages or on extra notebook paper--unless it's a really big change that involves thousands of words--then stick to the computer. :) This is the time to fix big plot changes, flat characters, tension, reactions, emotions etc.
Step Five: Take a purple pen and read through your manuscript, this time searching out your descriptions. Not enough? Purple pen to the rescue. Too much? Cross some out. Not written to your satisfaction? Melodramatic? Cliche? Cheesy? Purple pen. Anything that has to do with descriptions, tackle now.
Step Six: This time, with a pink pen, check your dialouge. Mark the passages with too little dialouge, and the places with an overabundance. Mark where you lose track of who's speaking, or if too many sentences start with "I". All your dialouge problems should be fixed in this step.
Step Seven: Read through your book again, this time with a green pen. You're going to check now for places where you could use 1 word in place of 10, or where words are repeated too closely together, you use the word in the wrong context, and that sort of thing. This is getting more into the details, and by now you probably have a rainbow-inked manuscripts, but don't worry--you're close to the end!
Once you finish Step Seven, you're going to have a book full of different colored markings, sticky notes, and scribbled memos. This is the time now to go through your novel on the computer, fixing all the things you marked in the manuscript. By the time you're done, your book will be much better, and should be ready for line-by-line editing stage.
Don't worry if this color-coded editing process takes a long time. That's ok, as long as you don't stop for months at a time. (That can make you forget things about the book that you need to keep in mind whilst editing). Each step may take anywhere from a couple days to a couple weeks, depending on how much you need to fix, how long the book is, etc. And if you have to rewrite a lot in Step Four, feel free to go back to Step Two and check through things again. In fact, that would be the good thing to do. ;) lol!
So that's my color-coded editing process. If you try it, I'd love to see a picture of your colorful manuscript! You can send me one at email@example.com. ;) Also, I'd like to know what techniques you use for editing right now. Please let me know in the comments! :)
You all have a lovely day,