Make a Scribophile profile.
Put your skills to work, giving free feedback to some of the thousands of aspiring writers on the platform. Next time you get an interview, give a presentation showcasing your work and the feedback you received from the aspiring authors. It will allow you to showcase your skills and show the potential employer you are passionate about the profession.
There are a lot of ways you can do this. I think you should treat it as if you were working. That means you need to meet specific editing goals per hour. http://stc-techedit.org/tiki-index.php?page=Benchmarks+for+Estimating+Editing+Speed
Provide all levels of editing, and showcase your work and the time it took you to accomplish. That means for at least one week, do an 8-hour day meeting the industry expectations. Then showcase the work. You can use a workflow app to track and document your "sample" weekly output. If you know what workflow app the job you want uses, try and use that one, but any popular one will do.
You need to stand out to get noticed, and this can accomplish that. It will also show a potential employer you are willing to put in the work and can handle the demands. In addition, by showing familiarity with workflow apps, you are already ahead of many potential candidates.
Of course, this can backfire if the interviewer doesn't like the work or finds it below standards. That's life. Best of luck regardless of what job you want, but try to find a way to stand out.