Which short course helped you get hired? - any advice?

I am considering a short certificate to improve my chances as a graphic designer. It has been weighing on me all week. I can study evenings. Which ones are overrated?

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.

A hands-on course with a project helped more than a purely online one.