Make sure every character has “A Limp and an Eyepatch”. Every character has to have a unique way of speaking, but also something memorable that will stick him in the reader’s mind. The reader has to have a visual clue, often a running visual reminder, which makes remembering a character easier.

Is this technique “fake” or “artifice”? No, it’s screenwriting. It’s the job. So when you find yourself with one or several unidentifiable characters who are getting lost in the shuffle, try saying what I say now all the time: I think this guy needs A Limp and an Eyepatch.