Build around education, projects, volunteering and relevant part-time work. Explain the tools you used and the contribution you made. Coursework is most useful when it connects to the opportunity you are pursuing.
Read the document out loud. Check spelling, dates and the reading order of your PDF. Ask someone you trust to review it. Keep a separate version for each application so you can tailor your introduction without losing earlier work.
Changes are saved in this browser. Export a draft file for safekeeping. Clearing browser data removes locally saved resumes.