First drafts are often brain-vomit and hence crappy. You can polish those initial ideas with your own editing skills and make it shine.
- Take a break from the first draft after you complete it. It can be a few weeks to few months. Come back to it later with fresh eyes and read it like a reader. You will notice many typos, plot holes, and redundancies. Mark them down and fix them.
- Run it through a grammar check software. Grammarly, MS word or any other free/paid online/offline software can come to your aid.
- Weed out the filter words, repeated words, and adverbs. Look out for these filter words that we tend to use often.
- Check the point of views you adopted. Are there errors in the way you have written the scenes? Check these tips to avoid them.
- If you want to make major changes to the first draft, create a re-writing schedule and outline the details you want to incorporate.
- Do not hurry through the rewriting schedule. Do it with as much enthusiasm as you had dedicated to your first draft.
- Check the pacing of your story. Use the exploding a moment method to slow down the pace in important scenes.
- Write detailed character sketches and incorporate these details to flesh out your characters.
- Re-establish the goals and motivations of your characters. After creating a detailed character sketch, you might want to incorporate some major changes in your characters' original goals.
- Did the characters undergo changes in your story? Write a detailed character arc.
- Are the transitions between the scenes smooth?
- Are there anachronisms, research errors or similar mistakes? Correct them.
- It is always good to use a simpler word instead of an uncommon word. Replace complex words with their simpler alternatives. Apps like the Hemingway Editor can help you with this.
- Check whether you can start the novel at a new place in your draft by moving around the scenes a bit. You need to create a hook as effectively as you can. You may have to rewrite the first chapter entirely or remove it.
- Send the finished second draft to your trusted beta reader for feedback. Once you get it back, if you find the suggestions worthwhile, adopt them. Repeat.