(MONEY Magazine) – As students begin their senior year of high school, most parents think that their kids are already lagging behind in the college admissions game. (If your child is savvy enough to want to get an early start, see "The College Admissions Calendar" on page 46.) But what if your child really has waited until senior year to begin choosing a college? Not to worry. It's still not too late for him or her to do everything necessary to receive that fat envelope containing a letter of admission to a college of choice. Here are the steps that high school seniors and their parents must take:

Stay calm and organized. One of admissions directors' most important messages to high school seniors and their parents is this: Don't panic. In fact, autumn of senior year is exactly the right time to submit to college interviews and prepare applications for admission and financial aid. And it's not too late to visit college campuses. The key: coordination. Have your child keep a datebook, post reminders on the bathroom mirror, or start a filing system where information on each college can be kept--whatever works in your family. Remember, a late admissions application may be rejected, regardless of the candidate's strengths. Moreover, late financial aid applications can make a student ineligible for most grants.

Enroll in challenging courses. "Ask any admissions officer what three elements are the most important in an application, and the answer will likely be courses, courses and courses," says Joseph Allen, vice provost for enrollment at the University of Southern California. Like most admissions officers, he believes that the best measure of students' potential in college is their academic performance in high school. "The transcript speaks to us about the level of motivation," Allen says. "Has the applicant challenged the available curriculum or taken the easiest path through school?" As soon as high school opens, he suggests that your senior enroll in the most challenging classes available to him or her--preferably, honors or Advanced Placement courses. If it's too late, he advises your child to enroll in such classes next semester and make note of that intention on college applications.

Zero in on SATs. Scholastic Assessment Test scores are probably the biggest source of anxiety for college applicants. Can last-minute cramming boost them? "Test preparation is like any other skill development," argues Frank Gallo, a national director of the Kaplan Educational Centers, which offers 12-session SAT preparation courses for students across the country at a cost of $495 to $695, depending on the region. Kaplan advertises that its courses boost a typical student's SAT scores by about 100 points. But this is disputed by officials of the Educational Testing Service (ETS), which administers the SAT, who say the gain is probably more like 50 points. Still, the courses can teach helpful test- taking techniques, familiarize students with the exams--if they didn't take them in junior year-and calm jittery nerves. "The major advantage of these courses is that it forces students to sit down and learn about the test," says Don Powers, a research scientist at ETS. However, Powers feels that most students would be just as well-off spending three hours with the ETS study guide Taking the SAT, which they can get free from their guidance counselors at school. It includes a sample test and tips for taking the test. If that's not enough, your child can prep for the SATs with a book, such as Princeton Review's Cracking the SAT ($15.95) or, for real late starters, Kaplan's SAT in-a-Week ($9.95), which is packed with helpful last-minute hints. Moreover, since scores generally go up with experience, if your child does poorly on the SATs in the fall, he or she can take them again in the winter or spring.

Rethink extracurricular activities. Most applications ask for a list of accomplishments and extracurricular activities. As a result, some students rush to sign up for as many things as possible during senior year. "These students are missing the point," says Michael Steidel, director of admissions at Carnegie-Mellon. He explains they are transparently trying to improve "the look" of the application, "and that screams of superficiality." Most admissions officers find a person with a single interest, pursued with passion, far more appealing. Thus now's the time for your child to take on additional responsibilities in a campus organization. It's not too late, either, to become involved in a worthwhile community service project.

Get the right letters of recommendation. Another benefit of a deeper involvement in an extracurricular activity or project--even one that lasts for only a couple of months-is the chance to cultivate a relationship with a teacher or adviser who can write a strong letter of recommendation. College admissions officers prefer letters from a few people who know an applicant well, rather than a stack of missives from important-sounding people who hardly know him or her. A compelling recommendation can come from a teacher who gave your child a B but speaks of his or her tenacity in pursuing a subject that did not come easily.

Visit colleges as a family. If you are just beginning to tour campuses, you're going at an ideal time, since you will see college life while school is in session. But it's important to cover considerable ground on each visit because your child will probably have little time to return before applications are due, usually by January. To get the most out of a visit, Daniel Walls, dean of admissions at Emory University in Atlanta, recommends that parents and kids split up, then compare impressions afterward.

Make personal fit a priority. The idea of choosing the right college implies that among the more than 2,100 U.S. institutions of higher learning, there is a single, magical campus that will meet your child's needs better than all others. But as USC's Allen points out, "This is simply not true. There are several colleges that will enable someone to reach academic and personal goals." It's critical, however, for your child to find a correct match. Allen advises you to be honest with your kid about how much money you will contribute toward college costs and which schools, if any, are unacceptable for geographical or other reasons. Kids can then carefully assess their own needs in making decisions about which schools to visit--and which one to choose in the end. "They must convince the admissions committee member who reads their applications that they have done their homework and know what the college has to offer," says James Scannell, vice president for enrollment at the University of Rochester in upstate New York. Nothing is more likely to disappoint admissions officers than an applicant who appears to have merely wandered around campus, asked no questions, paid no attention to what the college offers--and clearly should be applying elsewhere.

Learn about last-minute options. There are moves that can be made as late as May, June and even well beyond that. Your child's guidance counselor can direct you to colleges that remain open to new applicants through the summer. And local community colleges usually accept applicants through the first week of classes; credits earned at them can usually be transferred to a four-year college. If your child has a particular four-year school he or she would like to enroll in eventually, talk to an admissions officer at the school to find out which community college courses will be accepted for credit--and, just as important, which ones will boost an applicant's chances of admission.