Nothing now. FIREd last year. :D
When I did work, I was a graphic designer/illustrator.
Arty folks are here in small numbers, but it is mostly STEM and educational careers that make up the majority on this forum.
I never earned the high salaries that I've seen on this forum, but I was making way better money than 99% of my friends in the same field, and had some awesome benefits (but the workplace was insane and I'm still suffering the after effects). It helped enormously towards our savings/investing goals, and for some years before I quit, I was maxing my 401k and two IRAs, paying all medical and living expenses, and saving a small portion of my salary and all of my husband's salary. I think our savings rate was like 70% the last couple of years.
Full disclosure: While we were doing really, really well on our own, I was accelerated to FIRE by an inheritance. It shaved about a decade off my FIRE plans.
If you're in the marketing/ad industry, you'll need to live in a big city to make any sort of decent salary. Which may not be an issue for you, but if you are looking to save lots of money, living in someplace like NYC or LA for instance is going to cost a whole lot more than someplace like Austin, TX or Miami, FL. So doing research at least a year out about what sort of marketing/advertising you'd like to get into and what cities appeal to you (and if the two could match up) might be prudent.