A few random notes ...
Traditionally there have been editors and copy editors who will address the content and nuts-and-bolts construction of your book, respectively, but while both can sometimes save you from yourself, sometimes they can't.
The small stuff slips past.
Gave your heroine blue eyes in the first book of your new series, then green eyes in the second book? Chances are your CE won't catch that, because you usually won't get the same person from novel-to-novel. I know this from experience. (Fortunately, in science fiction, you can, if you finally do catch such mistakes, sometimes fix them. Blue eyes there, green there? Why that's due to droptacs, which come in colors. Or, um, you know, an alternate reality ...)
The late Avram Davidson used to tell a story about reading a student manuscript. The hero is climbing up a sheer cliff face, monsters climbing up after him. He looks, up, sees more monsters appear that the top, waiting. He's trapped. How can he escape? And the student actually writes: "Oh, wait I forgot to tell you, he has wings ..."
It's not a bad idea when you start out to do a quick character bio, with a physical description of your character. Any time you put in new stuff showing your reader what this player looks like, or where she went to school, or how many siblings she has, refer back to the bio until you have it nailed correctly. Use the same ruler, you get the same measurements.
Prop continuity is another one. If your character lost his cell phone in Chapter Two, but makes a call in Chapter Five using a cell phone, where did it come from?
Ever notice in the movies how the hero's gun is cocked, then not-cocked, then cocked again, in the space of a couple of screen-minutes? That's because the continuity guy screwed up.
Don't be that guy.
How many times have we seen some moron rack the slide on his pistol to chamber a round, then holster it, then a few minutes later, rack it again? Once is all you need, otherwise you are throwing live ammo onto the carpet.
Plot-devices sometimes require you have a character do something odd because you need them to be naked or unarmed or whatever in a subsequent scene. Be aware that there are clever ways to achieve this kind of thing. Go watch Die Hard and see how to set up stuff. Why is Bruce Willis running barefoot over broken glass? No better example, that, and everything else that gets paid off all the way through.
And, as long as I am here ...
For God's sake, if your hero is unarmed, gets into a fight with one of the bad guys, knocks him down, but LEAVES THE BAD GUY'S GUN LAYING ON THE GROUND and runs off, just so you can have him stay unarmed for the next fight scene? Come up with some kind of reason! Otherwise your guy is a dolt, an idiot, a lame-o, and readers will start rooting for the bad guy to put him out of his misery; surely I will.
You can have your character make a mistake, but past a certain point ... ?
Hey, Roy, didn't you just knock one of the minions out?
Yeah, I kicked his ass real good!
So ... why didn't you pick up his gun?
Um. I ... forgot ... ?
There's a well-known private eye character who usually leaves her gun at home. One fine morning, somebody up and took a shot at her, put a round into the front porch wall next to her head, thunk!
So the next day, the next day, when she went out, what did she do?
SHE LEFT THE FUCKING GUN AT HOME!
No! No! No! HELL NO!
Oh, yeah, I forgot. Somebody shot at me yesterday and it might be, you know, A GOOD FUCKING IDEA TO TAKE MY FUCKING GUN IN CASE THEY TRY IT AGAIN!
Why did the writer do this? She needed her heroine unarmed in a subsequent scene.
This is not how to do it.
Rather, this is stupid, stupid, and did I mention, stupid? and that's when your reader–certainly this reader–will put your book down and leave it there, never to darken your sales rack again. I don't want to read about a detective who doesn't have enough smarts to pour piss out of a boot. She's as dumb as the woman in the nightgown who goes into the graveyard at midnight looking for what made the unearthly moan. Take her out, and do the world a favor.
Be aware of time: Days, dates, how much has elapsed. If you switch viewpoints, and your players are living in the same continuum, be careful that you don't have one doing something out-of-synch when you switch POVs. Better not have both of 'em walking to meet each other for coffee one fine morning and one of them takes five minutes but the other goes home and takes a four-hour nap during the same five-minute span.
Unless, of course, it's time-travel or madness.
You can control typos and grammatical errors, and even though the spellchecker won't save you from using "see," when you mean "sea," it will collect some mistakes. Run it.
Having somebody with sharp eyes read your mss will help. When you write something, as often as not, when you scan it for errors, you aren't really reading what is on the page, but what you think you wrote. I'll miss the same typo three times.
One trick I've learned is to change the device upon which I'm reading. For some reason, I will now and again catch a typo using the iPad that I missed on the desktop computer screen. Couldn't tell you why.
There is another problem I have noticed in going to electronic publication, the transfer artifact. The file was fine when it left here, but by the time the publisher's conversion software got done with it, there were glitches that appeared in the final. Sometimes lines get broken like
so. Nothing you can do about that, nor the funny characters that show up as little hearts or or Ω other ding-batteries. I have revised some of those, only to have a different set show up on the next version.
Enough for now.
As with any rule-of-thumb, some of these can be ignored if you are a good enough writer. But if you are, you didn't need to read any of this, did you ... ?