This is advice for myself, and for anyone else who’s interested.
READ WHAT YOU HAVE WRITTEN
And follow this self-editing check-list
Run a spell check, then check the spelling yourself. The computer seems fond of playing the occasional joke.
Check the grammar. Sloppy grammar is fine when talking to someone (well, usually, anyway. There are exceptions!)
Does every passage add something? Does it take the action forward, or add something new to the subject? Or is it simply repeating what the reader already knows?
Are there mistakes in continuity? A friend of mine has written 74 books, and her editor still finds small mistakes such as the colour of someone’s eyes – brown on page 6, green on page 49. Double check everything.
Are there inconsistencies in characterisation? Or in motivation? Ask yourself – would this person really say this? Really do this?
Does a scene need expanding or, on the other hand, tightening?
Are you using narrative viewpoint effectively? In other words, can you take the reader inside somebody’s head and then keep them there?
I’m not quite ready to take the plunge. Are you?