EDITING.
Editing, as you write is one way of minimising the effort at the end of your novel that makes your novel sharper and grammatically correct, before you hand your masterpiece to a professional editor. AutoCrit is an easy to use program that guides the writer by identifying grammatical bloopers.
After using AutoCrit, the final edit must be made by a professional editor. I have used Jessica Stewart for my novels, and believe that she is one of the best. Go to her website to see for yourself.
Another handy App is Grammarly. The App provides continuous notification of mistakes that you may have made. See for yourself.