My D’s approach was something like Marian’s suggestion. She figured, at age 18, that she’d want to do something in science or math, maybe pre-med, maybe public health or something similar. (She knew she didn’t want engineering and her college doesn’t even offer it - or accounting or actuarial science or finance or anything else that specific). So she chose her classes with the idea of trying out a few different things but keeping her major options open as long as possible. She took the pre-med Chem, Bio, math, a language, a writing course, and continued to through this year. If a course she was considering satisfied 2+ majors she would take it over one that only satisfied one.
She now has chosen her major (not pre-med), is in a position to complete it on time, and has good career prospects. Some courses will count towards her current major, some won’t, but she will have everything she needs.
Many Us and liberal arts colleges have general education requirements (her college didn’t), and it makes sense to do those early both to get them out of the way but more importantly to try everything and see what feels like a good fit.