Look, I'm not exactly sure what makes a "good" vs "great" application (I do think I can tell when an application is "bad" though). There's a reason this industry is so profitable, and there's a reason that there are SO many resources online to create an application.

Organization

If you have a lot of colleges to apply to (or even if you don't), I'd STRONGLY encourage you to have an application tracker.Track things like how many LORs you need, whether official test scores are required, what the deadlines are, what major you're applying for at what school, etc.

Some tracker templates:

Also: create/use a personal professional email (NOT school email) for the college app process. you will get a LOT of emails.

Parts of an application

Most colleges have some, but not all, of these:

Some programs also ask for: video introductions, arts/maker portfolios, research supplements, graded written work, peer recommendation letters. Be sure you know ALL requirements of what a college requires.

Quick notes: Add your counselor to the Common App early so they can attach the school profile. Double, triple, quadruple check your grades. this is SO important, ESPECIALLY for the UCs. For standardized test scores: send official scores at least 2 weeks in advanceso you don't pay for express shipping.

The Additional Informationsection is for extra context that doesn't fit anywhere else. use it for serious personal circumstances, unusual course scheduling, clarification on activities. Don't use it as a second personal statement.

For resume: one page, easy to skim. Main benefit is more space than the activities list. Don't rely on it to carry your application. AOs may or may not read it. If you do submit one, I like Jake's LaTeX resume.

Building your story

What sets "top" applicants apart is having a story. Your application is meant to build a narrative about you that is cohesive and understandable to admissions officers. Each part should contribute something different to this story: ECs, essays, course selections, even recommendations.

Some people have stories that come very naturally together. Most high schoolers are not like this. That's okay! It just means finding a way to simply explain how the different things you've done naturally lead into what you want to do in college and the world. (This is basically what people are talking about when they talk about a "spike.")

Activities list + awards

Common AppUC Application
EC slots1020
Description150 chars~300 chars
Awards5 in separate Honors sectionIncluded in 20 slots
TipWrite your UC list first — longer descriptions let you find your strongest framing, then condense for Common App.

The way you write your activities list can mean the difference between acceptance and rejection:the AO can't understand how impactful/interesting your ECs are unless you TELL THEM.

I know some of you are reading this before you have to apply. Defining yourself by your ECs and activities list might get you into a top college, but it might also wreck your mental health in the process.

Please don't push yourself past the point of burnout. Applying Sideways | MIT Admissions is one of the best things I've read on this. Also: Let's Talk about Activities and Extracurriculars (AdmissionsMom).

At the same time, if you're in a competitive area, everybody around you is working really, really hard, and there is ALWAYS someone working harder than you. Find YOUR balance.

Personal statement

This is definitely the part of the application I struggled with most, like a lot. I actually submitted two different personal statements: one for my EA schools and one for my RD schools. After truly endless hours of brainstorming, revising, editing, crying, I can confidently tell you…

I don't like either of them. Unfortunately. Yeah.

The personal statement is a story/narrative about you: who you are as a person, what you care about, and an implicit argument about why a college should take you, no matter what prompt you choose. That's a whole lot to ask of 650 words.

Things I WISH I had done to make this easier:

Supplemental essays

Beyond the Personal Statement, selective schools will require supplemental essays. These gain a deeper understanding of you, what you value, and whether you fit the college's environment.

Supplementals can range from 50 to 650 words. Common prompt types:

Why School?What specifically about this school, and how will you contribute?
Why Major?Why do you want to study what you want to study?
DiversityWhat makes you unique? (likely renamed post-DEI laws)
LeadershipHow have you shown initiative in your community?
ChallengeHow do you overcome disagreement or adversity?
ExtracurricularWhat EC do you care about most, and why?
PersonalityWhat brings you joy, three words to describe you, etc.
Major / HonorsProgram-specific questions, honors supplements, etc.

Between EA and RD, I wrote around 70 supplemental essays. However, because you can group supplemental essays into categories, in reality you're only crafting around 5-8 essays about you. Some friends grouped schools with similar prompts and answered them all at once.

The big thing to do with supplementals is to use each one to reveal a different part of you. College apps are NOT a resume dump. being more accomplished on paper doesn't guarantee anything. Colleges in the US are communities, not awards shows. How do you add to them?

Letters of recommendation

Hopefully, you built great relationships with your teachers. If you didn't, well, find the ones that hate you the least.

Generally, you want around 3-4 LORs: 2 from teachers (1 STEM, 1 Humanities), 1 from an external source (professor, coach, job supervisor), and one extra if you want. Reach out around May-June of junior year (the latest being September of senior year).

If you go to a large public school, figure out when you need to submit your LOR form early. counselor deadlines tend to be firm.

Strike a balance between reminding your recommender and remembering they have a life outside of your college apps. There tends to be an unofficial grace period for recommenders. And be very grateful. maybe give a gift, write a nice card.

Demonstrated interest

Many schools publish their Common Data Set, where we can see what they value. One factor is "demonstrated interest": how much you've shown the school that, if admitted, you will attend. Schools can track this through: mentioning specific programs, meeting admissions officers at events, emailing your regional AO, requesting optional interviews, attending info sessions and tours, attending a summer program.

I can't really speak to this because it was one thing I never really did. However, schools like Barnard, Northwestern, and Rice all consider it at least a little. These are also likely to be schools that take many people ED.

6 Things to Know About Demonstrated Interest (College Essay Guy)