Updated: 29 September 2021

Primarily based on my personal experience as an undergrad (1999−2003) but folding in my observations as a professor, I have a mental model¹ for what undergrads should do to be successful. This page outlines this strategy, geared towards students (1) at the University of Hawai`i at Hilo and (2) aiming for graduate school in the sciences. Regarding (2): Even if one is not planning on graduate school, it is a winning strategy to aim for it, because it is easier to turn away from that path than to turn towards it.² Regarding (1): if you have ended up at this unlisted page, then I trust you can sift out the applicable information (e.g., maybe your institution does not have a Space Grant program but it does have an equivalent in-house funding source for research).

So on to my advice:

• Letters of recommendation will be immensely important (if not the most important) components of any application—for grad school and for any professional job. Good letters come from positive, long-term, and in-depth relationships because a letter writer is external evidence for why you deserve admission (or the job). Start forging these relationships early with your professors and the faculty and staff of your department.
• If you are a gender, race, ability, etc. underrepresented in STEM, you should be sufficiently comfortable with your letter writers to tell them: there are concerns without letters for underrepresented groups are written. Provide them with resources on the concerns, specifically for letter writers, e.g., gender bias and racial bias.
• This is a lot to digest but we are talking about a multi-year strategy. Find someone to mentor you, not in research, but in your undergraduate career (and/or life). This might be your faculty advisor but it might be a professor you connect with.
• If you are interested in grad school, you have to do research as an undergrad. Ideally, you would participate in several research projects (like a couple summers) or one project for a long time (like a calendar year).
• For a snapshot of what makes for a successful grad-school application, here are my personal statement and resumé from my successful 2003 application to UCSC, where I graduated in 2009. There are art and strategy to well-crafted personal statements and resumés; please feel free to contact me about them. (Once an undergrad who I was helping commented that my undergrad resumé was impressive; to which I responded that the point of a resumé is to impress, that partially comes from careful crafting.)
• But you have to be a very good student. Please do not get so involved in extracurricular activities your academics suffer, especially early in your undergrad career, because those are foundational classes.
• Also be sure to be taking the right courses each semester so meet with your faculty advisor early and often (do not just trust Star or the Advising Center.)
• Develop a sense of what job opportunities are out there and are interesting to you so you can choose courses that help you develop the skills to get such a job. I recommend perusing the American Astronomical Society Job Register regularly; it's updated monthly. You can find jobs for undergrads, for post-baccalaureates, etc.
• You will be most effective at research and competitive for prestigious opportunities when you are a junior, because you will have completed fundamental coursework, developed general skills (like programming or lab procedures), and—ideally—had some research training.
• So, to be in such a position, I recommend you try to do some simple research as early as possible.
• Network to find someone who might have a research project suitable for your skills and knowledge. So much happens through networking!
• You might attend interesting talks at the observatory headquarters and talk to the local scientists. You will see notifications about those via the majors' email list (uhhpamajors-l, see more about UH LISTSERV here), but you can sign yourself up directly for the EAO talk list here.
• It is easier to obtain a research project with someone at UH Hilo than almost anywhere else because our job is to train you. So just start asking around. But be prepared:
• read about what the faculty member does (either via their personal website or the Departmental page);
• be ready to explain your interest and ability (can you program, operate a telescope, prepare a slide, or just explain what relevant courses you have taken); and
• be clear about what you are willing to give. People protect their time and do not always have funding. So are you looking to do research for free (as a volunteer), how many hours a week? Do you need to be paid? Would you want to do it for credit via an independent study? et cetera.
• Now here are three levels of research opportunities you should aim for, in order of competitiveness:
• Hawai`i/NASA Space Grant Traineeship or Fellowship: These are funded academic-year positions, that can be sponsored by any qualified professional (e.g., someone from an observatory could be the advisor). Our Department has been very successful helping students get these (close to 100%). Proposals are due Jun 15 for a fall position and Dec 1 for a spring.
• Akamai Internship: This is a paid 8-wk summer internship on Hawai`i, Mau`i, or in Pasadena, CA, for Hawai`i residents or UH students, in more than just astronomy. There are usually about 25−30 positions and over 100 applicants, so this is more competitive than a Space Grant. Applications are due in early February.
• National Science Foundation Research Experience for Undergraduates (NSF REU): There are paid 8- to 10-wk summer positions across the nation (and a few abroad), in many, many fields (you can search). These are very competitive. For reference, my friend runs one and has six positions and up to 300 applicants. One has to have conducted research to be competitive. Applications are due between December and March.
Just put it on your calendar to apply to the various research opportunities. (Like, right now, put "Apply for Akamai Internship" for Jan 15, 20XX and 20XY, where Y = X + 1.)

¹ In spring 2021, I asked several colleagues at other institutions with astronomy graduate programs that were no longer requiring the Physis GRE: what do you base admissions on? (The why behind this "GRE exit" is explored here, here, and here with link.) I received responses from faculty at UT Austin, U Chicago, Vanderbilt U, New Mexico State U, and U Washington. Many pointed to a rubric their departments had developed to assess an applicants qualifications.
The gist is that the "strategy" I outline here is correct: research experience and letters of recommendation really matter. One other really interesting point, one colleague said, in her experience, applicants with a GPA less than 3.5 almost never get accepted to PhD programs, which backs up my fourth bullet point: be a good student first and foremost.

² Currently, I believe most K-12 preparation in the United States is weaker than in the past. This has led to most employers requiring a bachelor's degree for jobs that used to not need it because most undergrad programs spend time teaching what once was the purview of K-12. Since this is the case (again, in my opinion), jobs that used to actually need a college degree now require an advanced degree. This is "degree inflation," which means most undergrads should plan to obtain an advanced degree; a STEM master's degree is optimal for lifetime earnings. As said in the main text, it is easier to aim for grad school and turn away from it, than the opposite.