This is a great question and one that I'm glad you are asking, especially with the current situation of overwhelming student debt.
The short answer is to avoid it. While that is easy to say, it is always easy to do and it will come with sacrifices.
Here are some things to do.
1. Look for and apply for any scholarship that apply to you. Hint, they don't all require great grades.
2. Look at local community colleges or tech schools. These are significantly cheaper and a great way to complete your general classes or your associate's degree. Then you can move on to an University for further education. Another benefit to this is it gives you more time to decide on specialty branches for your degree.
3. Don't feel like you have to complete your degree in four years. If you need to work full time and go to school part time that is fine. This also has the added benefit of giving you the work experience that will enhance your resume.
4. Along with all the above, start saving money now. Look for opportunities to pick up after school or summer jobs and save that money. Not only will you have money to use for school, but you will also have learned valuable budgeting and money management skills.