You just can't point to one answer and say it's THE only way to do it. Kids are different.
My kids had their first year paid for in full, then had to assume 20% of the cost beginning with the sophomore year - I wanted them to have a financial stake in the matter. Their share went up if their GPA dropped - and if you dropped below a 2.25 for two terms in a row, my funding of your college education ceased completely.
Three kids, three different results:
- One kid decided after sophomore year that they "wanted to experience the working world" - just in time for the bottom to drop out of the economy. He/she is now back in college on their own dime - two courses a quarter at TOSU/Columbus State while living at home (OK, rent-free - I'm not a total hard-ass) and working full-time. This kid will have about $14K in student loans when/if they graduate.
- One kid charged through college, and took full advantage of parental funding. This kid will have zero student debt - worked part-time all through the last three years, and borrowed $4K for their senior year As a graduation gift, we assume responsibility for the loan (we'll pay it during the six-month grace period) in recognition of the 3.8 GPA. (Don't tell the others this - but I would do the same for them as well, withing $$$ limits.

) Kid is interviewing for three jobs as we speak in their chosen area of study.
- Last kid received the academic death penalty, basically partying their way out of school (as in invited to not come back after freshmen year). This one dicked around with a community college in the same town for two semesters, but failed more courses than they passed (different school, same situation). They are now trying to survive on a $10-an-hour job while waiting for the "significant other" to find a job following graduation. This kid is debt free - but the SO has about $80K in college debt in a area in which graduates are lucky to make $30K per year, and hasn't landed so much as an interview. I sincerely worry about these two.
Ask the first and last about the value of a college education!