For folks who are close to the Foggy Bottom campus, the Center for Career Services has a self-service photo booth where you can take professional quality headshots. Book your 10-minute appointment by visiting their website.
If you don’t live near the DC area, this article offers some great tips on how to take a decent headshot yourself using just a smartphone. To take things to the next level, import your photo into Adobe Express and replace the background with one of their built-in templates.