Wonderful as words are, they can be slippery little suckers. Getting the right words in the right order onto paper to tell the beautiful story in your head can be a challenge.
A good editor can help but sending a new story to an editor immediately after one finishes writing it isn’t always the best way of going about it. It can be an expensive exercise when there are other steps you can take first.
Almost all writing teachers will recommend you give a new manuscript time. Leave it for as long as you can because coming back to a manuscript fresh after letting it sit can help you see what’s actually on the page, rather than what you think you wrote. When I began writing I remember rereading and discovering I had repeated what I already said, sometimes more than once.
Next step is to have one or two or more of your writer friends critique your work. This is often the job of a good writers group, trusted friends who read each other’s work, who may have been there while you brainstormed, plotted and wrote, may see things you miss. The pace of the story may have slowed, there may be plot holes which need filling, unanswered questions, impossibilities or inconsistencies.
If possible, also find some beta readers, or trusted persons who read extensively in your genre and can give you an honest opinion.
When you have considered all their suggestions, made any amendments and reread your manuscript again, then it’s time to send it to an editor. Earlier and you will be paying more for your editor to find those things your critique partners and beta readers or you yourself didn’t see.
Don’t be disheartened though, many experienced writers will tell you that they prefer not to read earlier published stories. Like any great artist, there’s always something which could have been done better.