You obviously need to be a top student, probably applying to top US schools.
You need lots of AP exams and perhaps SAT IIs with top scores, as well as meeting minimum SAT I requirements
You need to know exactly what you want to study. You need to have strong qualifications for that subject area, and you need to convince them you will learn using the tutorial system
ECs do matter when applying to Scottish universities, but not English.
For example, athletics doesn’t matter. Playing on a varsity team helps a lot applying to Ivies and is pretty much required for West Point. You also won’t get in because the coach wants you for a team.
Obviously, if you have relatively poor grades or ECs or are not considered well-rounded academically by US schools, Oxbridge or other British universities may be right for you.
You need to have or be able to obtain funds for tuition.
When you apply to UK universities, you submit a common application. You can apply to at most 5 schools, and you cannot apply to both Oxford and Cambridge.
You need one faculty reference. In England, this is usually from the equivalent of a guidance counselor, combining comments by different teachers.
This is much easier than in the US, where you need to send separate applications to every school, and people often apply to 10 or more schools.
British students spend there last 2 years in high school studying 3 or 4 subjects.
Usually, they are related subjects, such as mathematics, physics, and chemistry, or English, history, and French, or mathematics, economics, and geography.
It is considered a disadvantage in applying to university if you take a mix of humanities and science for example: it does not help to be well-rounded.
There was a famous case where a girl with 4 A*s was rejected by Oxford for medicine. The tabloids implied it was because of her lower class background. However, in addition to it being harder to get in medicine, her A-levels were in biology, chemistry, French, and English. They probably preferred biology, chemistry, math, and physics. In the US it would be an advantage showing she was well-rounded.
They take exams called A-levels: graded A-E; the highest grade is A*. These exams are advanced, covering what is considered college material in the US.
The A-level exams are all the traditional approach, essay or problems, no multiple choice. AP exams are mixed essay and multiple choice and SAT I and II are all multiple choice.
You cannot take A-levels in the US. In fact, British universities will often ask for AP exams for students from countries where you can’t take A-levels and there aren’t national exams the British have confidence in.
Universities do not look at grades from their teachers.
If you apply to British universities from the US, they are not interested in GPA or ECs. They are mostly interested in test scores. It is the opposite of the US in that AP exams are generally most important, then SAT IIs, and then SAT Is or ACTs.
When you apply to a British university, you apply to a specific department. At least at Oxford and Cambridge, it is the department that makes the decision. You will study only within that department and it is close to impossible to change.
For a US student, it is probably better to apply for a combined program. For example, you can study politics, philosophy, and economics (PPE) at Oxford.
You may be able to study biochemistry, math and finance, or math and physics.
Of course, it is fine to study one subject, if that is what you really want to do.
Programs at Scottish universities allow you to make a decision about field of study later and are not as structured as in England, but more structured than in the US.
About 30 US students from US high schools are admitted into Oxford or Cambridge every year.
By contrast, there are about 5000 freshmen at Harvard, Yale, and Princeton. It is easier than it used to be, but difficult because it is hard to meet their requirements with the more general US system. The British system probably gives a somewhat better high school education and is more rigorous, but the main problem is that it is more specialized.
Oxbridge is not really as competitive to get into than Harvard, Yale, or Princeton
For example, it is generally easier for students in other countries to get into Oxbridge than absolutely top US schools.
Oxbridge are big schools for a country with 1/5 of the population of the US.
In the US most college bound students study more or less the same thing, math, science, English, foreign language, and history/government. They also play sports and do other less academic things. There are obviously advantages to the more general approach, even if it doesn’t prepare you as well for Oxford or for a specific career.
Cambridge says they want 5 AP exams with a score of 5. You also need 2100 combined SATs. It is best if you can provide AP and SAT II exam results in areas related to the course you are applying to. AP exams cover smaller subject areas than British A-levels. Most successful US applicants provide many AP exams.
Generally, it is a stronger application if you have a lot of AP exams with 5s and high scores on SAT IIs in areas related to what you want to study. A single AP exam does not cover as much material or as advanced material as an A-level. Showing them a bunch of scores can make it clear that you have the equivalent of 3+ A-levels.A-levels cover a lot of material.
For example the Maths A-level covers the equivalent Calculus BC, AP Statistics, and AP Physics / Mechanics, as well as precalculus. So the equivalent of 4 college courses.
Similarly, the Physics A-level covers the material in 4 or 5 Physics AP exams.
This is why it is better to have a lot of AP Exams and SAT IIs to simulate 3 or 4 A-levels.
3 A-levels with A’s or B’s are maybe the equivalent of 10 or more AP exams, and thus traditionally more than a year of US college.
They will also accept the International Bachlaureate.
You need a minimum of 38 for Oxbridge. With 40 you have a good chance.
The IB is more general, similar to US high school education, whereas if you submit AP exams, you can simulate the more specialized British A-levels.
Some departments have their own exams which you will have to take.
Oxford does this more than Cambridge.
There are very difficult exams required by Cambridge applicants in mathematics.
When you apply to Oxbridge, you need to pick a college.
Your chances of admission may be greater if you pick a less prestigious college. Rankings of Oxford colleges, rankings of Cambridge colleges
They will sometimes move you to a less prestigious college, but this happens more often for Oxford than Cambridge.
I would recommend that most American applicants not apply to the more prestigious colleges.
The personal statement should be formulistic.
You don’t need to be unique like in the US
You want to stress why you want to study whatever you are applying for.
You want to indicate lots of reading you have done in the field you are applying for.
If you meet the minimum requirements for Oxbridge and they like your application, you will be invited for an interview. It is preferred that it be in person, but you can do it over skype.
The interview is not at all like a US interview. It is with the faculty of the department you are applying to.
You will be given something to read, something to translate, or some problems, depending on the field, and will be asked questions on it. They want to see how you learn with their tutorial approach.
There are British firms that will do practice interviews for a fee and it is recommended that you use their services.
International tuition is something like $32K/year, which is much more than for UK students, but less than most top US private colleges. The universities do not provide financial aid, but you may be able to get financial aid or loans from other sources.
The UK system is does not require UK students have a lot of money for tuition. You cannot buy your way in, and there are less hooks, but there may be some advantage to going to elite private schools and having high-class connections.
It is based on knowledge of very advanced material, which gives an advantage to English private “public” school students and those from upper middle class state schools.
British students usually receive conditional offers.
Their faculty reference predicts their scores on A-levels taken the senior year. The offers or based on those predictions and preliminary versions of A-levels taken their junior year. Offers are conditional on achieving certain scores.
If you are taking APs your senior year, the person writing your recommendation will need to predict the scores on them, and you are in trouble if the predicted scores are not all 5s.
You could receive an offer conditional on AP exam scores from your senior year, but if you have enough AP exams and SAT IIs it is possible for an American to receive an unconditional offer.
If you are applying for a Rhodes Scholarship, a lot of it is the opposite. This is usually after college. However, most still study for a second bachelors degree. You would need top grades, athletics, leadership, and other intangibles.