As suggested already by @happy1, gaining admissions experience as an undergrad should be the top aim for those hoping for a real admissions job after college. Most colleges have positions not only for tour guides but also for admission office interns (which may be paid jobs). Admission offices typically employ work-study students as well.
TIP: At many colleges, tour guiding is a selective position, with students evaluated and chosen by peers. While this process has pros and cons, it can sometimes pass over potentially excellent guides who don’t quite fit the college’s tour-guide mold. But colleges can be desperate for summer guides (a paid job) who are hired by the admissions staff directly and not necessarily members of the term-time guide group. A summer guide gig can be excellent resume fodder for an admissions-dean wannabe.
For those who don’t land an admissions position straight from college, consider earning a Master’s degree in a related field (e.g., Higher Ed administration, counseling, public relations, psychology, even marketing) and then trying again. I personally feel that an advanced degree is not at all necessary to be a good admissions official, but I’ve also been around enough hiring processes to see that it usually helps.
Other factors that have come into play in the admissions-hiring processes that I’ve been privy to:
-being an alum of the college that is hiring (mentioned above). It’s not an imperative but usually a big plus
-if not an alum of the hiring college, being an alum of a similar type of college (women’s college, large public university, small liberal arts college, etc.) can help
-bringing diversity into the office. I’m not just talking about racial or ethnic diversity but all sorts. For instance, when a college is trying to boost the numbers of STEM majors in the freshman class, but no one on the admissions staff has a STEM background, priority may be given to a STEM major when there’s a vacancy to be filled.
Of course it’s often hard for prospective employees to know if such priorities exist, but the wording of a job notice does sometimes give a hint. For instance, if the job description includes, “Organizing multicultural events,” then chances are good that the college is seeking a person of color. The job descriptions may also hint at which academic backgrounds (STEM, business, liberal arts, etc.) will go to the front of the line.
It’s common for students who have served as tour guides and admission interns to apply for real-world admission jobs right after graduation. And it’s also common for these young admission folks to move on to grad school or another field after just a few years, creating frequent openings in most admissions offices. But these entry-level jobs are so often filled by applicants who already had admission experience before graduation that applying for such positions without it is a real liability.