Do you enjoy fast food or going into retail shops? Many companies hire mystery shoppers to test the customer service of their stores. A common one is Subway, which hires mystery shoppers to ensure that "Sandwich Artists" are following all the franchise guidelines. If you have time and can travel to different places, this could be a good side hustle.
Apply for new scholarships and grants. A lot of students think that they are only eligible for funding when they initially apply for admission. This is a mistake! There are often new scholarship opportunities for upperclassmen, though they aren't always widely advertised. You may also be able to apply for external scholarships or grants, which are offered from groups outside of your school.