Before entering graduate school, I spent time in various regions of Peru working in the field as a biological anthropologist. I made castings of pre-Incan skulls that I would later analyze using electron microscopy. Although I ultimately traded the field for the lab, my time in South America was truly both challenging and life changing. I am greatly indebted to Tiffiny Tung (Vanderbilt University, Anthropology) for opening my worldview.
I also used to build race cars. 3 years of my undergraduate was spent as part of Vanderbilt's formula SAE program learning machining, composites work, data acquisition, computational modeling, and project management. I was manufacturing lead for 2 years and design lead for 1, capped with a design face-off with the only female scrutineer in Formula 1 (I was honored). I highly recommend these sorts of programs as great hands-on experience.