If your school is lucky enough to have an on site restaurant it is probably the best way to give students the most practical experience and raise money. Usually culinary program run restaurants are only open for breakfast or lunch and offer a lower cost menu for the community.
By law culinary programs cannot compete with their local food service, however this does not apply to faculty and staff. Some schools have their students take lunch orders from faculty and deliver their lunches to their rooms in a boxed lunch fashion. Another way to do it is to host the lunch in the culinary or faculty room itself and have faculty and staff pay at the door. This gives the students the opportunity to practice both the front and back of the house.
One of the highlights of fashion design or sewing class can be a fashion show. Fashion design students put on an annual show calling formal wear companies to borrow dresses and tuxes, as well as local hair and makeup salons for their services. Other groups like culinary or hospitality can get involved by selling food. Teachers can even be invited to wear their old prom dresses!
Another great way to teach students how to bake in mass quantity, maintain quality control, and market food attractively is to sell boxes of several kinds of Christmas cookies. My students made boxes of 3 dozen Christmas cookies including peanut butter kisses, chocolate crinkle, Russian Tea Cakes, gingerbread, sugar, raspberry thumb prints and coconut macaroons. The community generously supports the fundraiser often profusely thanking me for making their holidays easier.