Of course, to make a private tour, designed exclusively according to your wishes, and not spend a penny of their own budgets is possible only in case of sponsorship from any side. However, around a lot of other opportunities that will allow you to forget about banal tourist status and make much more useful and exciting journey.
Internships and academic exchanges
Typically, internships abroad are associated by the layman with a serious cost. In most cases it is so that when you query in a search engine you will find dozens of companies offering you to go to study abroad for quite a decent amount. Meanwhile, there are tens of active programs, in which all your expenses will be fully compensated by the organizers. Among the most famous of them, AEGEE, Erasmus, DAAD, Fulbright Program, MACA.
In some cases you will be required to pay expenses on the road. Do not just discard these options: sometimes in such a program students are paid a stipend, are able to cover these expenses. Separate programs free fellowships and grants abroad you can find directly on the websites of the universities where you would like to learn.
The volunteer movement
Don't think that volunteering is a synonym of self-sacrifice for those who have nothing else in life. This activity is not only an undeniable benefit to people, but also means a very exciting trip, meeting new people, exploring amazing places that you are unlikely to have visited as a banal tourist. If you are willing to spend a lot of time on the road, you don't have small children (or, on the contrary, they've grown up and independent), if you are not afraid not the easiest job, look for information on projects in the West's largest volunteer organizations, Conservation Volunteers, WWOOF, United Nations Volonteers (UNV).
If you do not want neither to study nor to work, nor to help people, and just travel - there is a solution for you. Every year, gaining momentum in the development of guest networks: online communities that help everyone are free to travel the world. The largest of them - Couchsurfing, Bewelcome, Hospitality Club.
The basic idea of guest networks - bezposrednia mutual aid members of the community, thanks to which you will be able to make new friends, free to stay in homestays, visit the unforgettable sights, accompanied by a friend from this country. Participants often guest networks looking for travel companions for a trip abroad by car, for the company: in this case, you don't even have to pay for a ticket.