I have a few thoughts on letters of recommendation that I want to share. Most schools ask for two or more letters and you will want to send a minimum of three letters (and likely a maximum of four). Given that this is a relatively small number of letters, you will want to carefully consider who writes your letters and what type of picture is portrayed to the reader in these letters. But the most interesting and useful guidance for letters that I have received from a director of admissions was that law schools evaluate applicants principally as prospective law students, not as prospective lawyers. This means that you will want a minimum of two academic references writing your letters. These letters tend to do significant work for you in the admissions process because they speak to the applicant’s ability in an academic setting (i.e. ability to critically analyze text, contribute to a classroom discussion, quality of writing and research, etc.). Letters coming from outside of an academic environment (e.g. a professional reference) often speak less directly to the skill set and abilities law schools prioritize. These letters can provide additional dimension to you as a candidate but you want to make sure that these are relevant and impactful dimensions. (For example, your ability to innovate in the work place may not be as relevant to a law school as it is to a future employer.)
Thinking a bit more about the content of your letters, you want to think about the kind of letter you believe the professor or advisor will write on your behalf. Obviously, you will want to have done well in the class taught by the professor. But you will also want to think about how many different reference points the professor has with you. For example, if you take one class with a professor and do well (good grade, robust participation, good feedback on papers, etc.) then the professor can write a solid letter. But, if you take two or three classes with a professor, they can talk about all of the things mentioned previously plus your performance across subject matters, success in requirements in various courses, your intellectual development, etc. (Personally I think intellectual development is particularly useful.) Moreover, if you have had contact with the professor in extracurricular contexts (honors societies, Minerva house events, public lectures, etc.) then they have even more material for the letter. Again, I think it is quite useful to try to envision the kind of letter you think the professor will write for you and you can begin to think about whether there is sufficient information for an impactful letter to be written.
Once you’ve thought about who it is you would like to write your letters, you need to contact them. Do this early. I advise students to first contact their references in the spring term of their junior year (assuming that the student is going directly from undergrad to law school). You do not need to do much more than contact them and have them agree to write the letter. Tell them that you will then contact them again in August with the LSAC letter of recommendation form, which they will need to submit with their letter. This accomplishes two things: First, it does as much as possible to assure that your letters will be submitted early in the process. The last thing you want is for a professor to slow down (or halt) your application because they haven’t submitted your letter. Not only can this hurt you when the school has rolling admissions but it puts you in the awkward position of having to pester your professor for the letter. Second, it makes you look highly organized, which is a good impression to give before someone is going to write a letter on your behalf. I hate it when a student asks me for a letter and then gives me a short timeline. This is very frustrating and it impacts the quality of the letter. You want professors to be able to draft and revise their letters much as you draft and revise your personal statement. (Although professors almost certainly will not work through a dozen drafts of your letter.) Keep in mind that some professors write many letters each year and this becomes quite burdensome, especially in the fall term. Give them the time they need and they will appreciate you all the more.
Lastly, after your letter of recommendation is submitted, write your references a thank you letter—not an email. Write them (as in pen to paper) a thank you letter (as in that stuff that used to be a tree). I can’t stress to you how important the thank you letter is. Writing a letter of recommendation takes a long time and it reflects positively on you when you take the time and effort (rather than something you wrote on your iPhone while standing in line at Reamer) to acknowledge those who made an effort on your behalf. I keep every letter I receive and I always think more highly of the sender after I receive it. (And, for what it is worth, my stack of letters is not nearly as high as it should be.) So, make this a general rule in your academic and professional life, write thank you letters.