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Take part time work while in school and during the summers to have some money on hand when you leave school. Start applying for work during your senior year, and keep the applications current. (Update and re-apply when necessary.)
If you are a musician/singer/dancer and have an act, consider busking in Europe. I did this for two summers. Europe has a more positive attitude towards this than America. I'm not talking about ragged homeless people. I'm talking about people who can play music, sing and dance. I have a friend who made over € 35,000 in a summer (that is how much he took home at the end of the season) just playing a celtic harp and occasionally singing, but he had CDs to sell along with his act. (You have to deduct what he paid for the CDs, but he sometimes took in € 600 a day)
I was in a two-woman team and we would bring in € 200-300 a day when we hit the right places (touristy places). Once you meet people doing this, there is a network. They can tell you where the good places are. And it fluctuates from year to year. It helps to have friends you can stay with as you travel, but you can sometimes find these by networking.
And ..... it teaches you about capturing people's interest. They will walk away if they are not interested. To capture and keep up interest on the street, you have to be good.