What I did during the last couple years of high school and throughout university was to do some jobs that I definitely didn't want to do for longer than a month, but where I was curious about "how they work from the inside". I did one-month stints at a fast-food chain, private tutoring for languages and math, cashier at a department store, and working in a bar, and short-term things like selling merchandise at big events. I also found two not-so-common opportunities through friends of friends (teaching in a bilingual summer camp, and helping with a TV program). The main criterium for me here was whether it was something I wanted to experience once (the bar paid much more than the fast-food chain, for example, but it didn't play any role in how long I was sticking with them).

I assume you're going to school in the US, so I'm not sure how much will be transferable from my experience being a CS/linguistics student in Germany, but FWIW: my other category of jobs was "helps gain professional experience in my chosen fields" (research assistant at university, part-time programming jobs at various companies) or "somewhere I can sit and study while being paid" (university library jobs FTW!).

Specifics:

• Being a research assistant at my department was great because I ended up forging a good relationship with my professors, got involved with research at an early stage, could apply concepts I was learning, etc, so it was both fuzzies (everybody went for drinks at the end of a semester, for example) and more tangible benefits (when I needed some recommendation letters for a scholarship, everybody was very happy to give me one even though they were busy).

• Finding part-time programming jobs outside was surprisingly easy - from what I know, it's much cheaper for German companies to employ students (you need to pay less benefits etc), so as long as you could write FizzBuzz you were already a net positive for them. Those jobs were the reason I was not completely lost at my first full-time job out of university.