Find a job announcement related to your career field. It should be a real job that you would legitimately consider or actually are applying for either now or in the future. Create a cover letter that must be tailored to match the qualifications of this job announcement and thus persuade the audience that you should be hired for this job!
Job announcement:
https://www.indeed.com/m/viewjob?jk=c27c66819793aaae&from=serp&prevUrl=https%3A%2F%2Fwww.indeed.com%2Fm%2Fjobs%3Fq%3Dmarketing%2520manager%26l%3DHagerstown%252C%2520MD%26from%3DsearchOnSerp%26sameQ%3D1%26sameL%3D1&ittk=AROCB2VGWI