When trying to avoid unintentional plagiarism in a rough draft or even final essay, it's always best to do a few things!
1. Run your paper through a plagiarism checker, (I use grammarly's).
2. Ask your prof to read through it. It never hurts to ask if they're willing to check with their software.
3. If you do have unintentional plagiarism in your paper, switch up the wording! This strategy works perfectly to even strengthen your paper!
Good luck on the paper xoxo <3