I have read a self-published novel that features a hero who is a specialist in intestinal worms. It starts with him in the lab, taking a stomach sample from a lab dog. You don't have to be into animal rights to think yuck. And he wore a vest.
2. Problems solved immediately, or left so long that we forget about them.
Another self published novel brought this one to mind. The heroine kept having problems, but the solution was immediately to hand.
'Oh no, this door is locked!'
'Oh, I've just found a key - do you think it might fit?'
3. Too much or not enough conflict.
Recently someone told me at length about their novel. It featured terrorists and spies, explosions, family dilemmas, a child with a heart problem, a royal kidnap, a romantic sub-plot. 'And I've nearly done 10,000 words!'
The flip side is one where nothing happens. You realise you're on chapter 5 and the characters still haven't made it to the meeting they set up in Chapter 1, and nothing else has happened either. Usually features lots of back story.
4. Plot clusters
Two (or more) dramatic events are crammed next to each other. Dramatic events need room to breathe, they need space around them for the reader to get full enjoyment from them. Shoving them next to each other is like overstuffing a vase full of flowers, the impact is lessened for each event. 'Yes, I am your mother,' she said. 'And by the way, he's your father.'
Think of your novel like a car journey from A to B. Sometimes you accelerate, sometimes you slow down. If it was nothing but acceleration, you'd feel you were hurtling out of control, but if it was nothing but braking, you'd gradually drop off. Acceleration is action, braking is reaction. You need both to get from A to B comfortably, although usually the pace picks up towards the end.
6. Chapter ends
And talking of gradually dropping off, never ever ever have characters going to sleep at the end of chapters. You're just asking for the reader to go zzzzzzzzz.
Character Fails tomorrow....
There are still some places on the How to Sell a Novel day course in Bath on 3rd July - clickhere or contact firstname.lastname@example.org if you want more info.