(This list is what I need to actively keep in mind when I'm writing as well hehe)
1. Re-read out aloud when you're done because it's more effective as a proof-reading technique than simply skimming through what you've written. Sometimes grammar mistakes are more obvious when we listen to sentences aloud.
2. Avoid cliched writing so when you spot a cliched phrase, try to phrase it in another manner! It makes your writing stand out and brings across something unique about your way of expression.
3. Get constructive feedback for your writing, from friends or family members or even members from the Write the World community. ;) Nothing beats a fresh pair of eyes to offer you insight as to how to improve your writing!
4. Write from experience, write about what you love, as that is when you can keep it sincere. People can tell when you're writing from the heart and it really makes a difference in their reading experience.
5. Keep writing, keep practicing, keep experimenting, keep rewriting. :) Nothing worth it comes easy.
Wishing all writers out there all the best in your writing endeavours!