Always read through your finished work at least twice, with decent intervals in between. You will pick up different errors on each occasion I promise. You will also wonder w hy you didn’t see such errors before. Give yourself plenty of time for reading your work through so when you do send it out, you know it’s the best it can be.
Your writing time is time for you. Having time for yourself should make you easier to live with so helps your relatives too!
Does your tale progress to a natural conclusion based on what’s gone on in your story? Your tale should have a series of peaks and troughs before reaching the climax at the end of the story. And the troughs must be as interesting as possible. They’re good places to drop in sub-plots and information your readers need to know but this should still be so interesting your readers won’t know it’s a trough.
Does your story “taste” good? In a fantasy/sci-fi world, have you worked out what your characters eat and how they do it? How is their government run? Even if that is not a major element to your tale, there should still be some indication of what it is as that helps make your world seem real. A “tasty” story leaves no loose ends but should make you wonder what happens to the characters after that finish. Is the tale something you can envisage happening to someone in some universe somewhere?
Use the senses. Jilly Cooper is a great advocate of the use of colour to bring scenes to life but use all the senses. We do. Why should your characters not do so? An odd sentence here or there is enough to add colour to your story in this regard.
What brings your character to the crisis in their life that forms the basis of your tale? Don’t put in a huge block of narrative to explain this, drip feed the information, but the stronger the character, the greater the crisis they can face. A stubborn person can create more crises for themselves than a passive one. And are your characters distinguished enough from one another to stand out?