Close attention to the whole transcript, for instance, can reveal that a student's grades have trended from freshman B's and C's to a junior year of mostly A's, and in rigorous, challenging classes—a likely sign of increasing maturity.
It doesn't necessarily follow that you have to load up with honors or AP courses that don't make sense for you. But students should clearly have placed themselves on a "trajectory that suggests that they're moving in a direction that's going to allow them to succeed in college," says Don Honeman, dean of admissions and financial aid at Clark University in Worcester, Mass.
If you've stumbled, consider being upfront about blemishes on your record. "Having grades of C or below in your transcript is not the kiss of death," says Amy Greenwald Foley, senior associate director of undergraduate admissions at the University of Delaware. But "having grades of C or below and not acknowledging them can be."
It's important to communicate what you've learned from the experience and how you improved (or will), and not make excuses or blame a teacher. A letter of recommendation from the instructor who has witnessed the struggle might do the job best, says Sharon Grice, director of admission operations at Cornell College in Iowa. He or she can talk about your work ethic, study skills, and dedication.
When the transcript and test scores don't say everything about potential, the admissions essay can be the place to shine. "I feel like my writing had sway," says Julia Yenco, of Jackson Heights, N.Y., who considers herself a born writer but for whom math was always a "thorn."
[Get tips for writing admissions essays.]
After making up a failed math class in summer school and conveying her enthusiasm for reading and writing in her essay and other parts of her application (she detailed, for example, her Saturdays of community service helping younger students with their writing), she was accepted at Hobart and William Smith Colleges in Geneva, N.Y. "I feel like I have all the room to grow there," she says.
What are some attributes of schools that serve late bloomers well? Counselors suggest looking for programs that ease the transition to college-level work, such as freshman seminars and living-learning communities as well as tutoring programs and more than just minimal academic advising.
In the living-learning communities at schools like the University of Wisconsin–Madison, Temple University in Philadelphia, Washington State University, and Elon University in North Carolina, students with similar academic or other interests live in the same hall, and sometimes take one or more classes together. Being part of a community of learners "where people will know you by name," says O'Connell, can be a really important ingredient of success.
Searching for a college? Get our complete rankings of Best Colleges.