Letters of recommendation are needed for hiring and promotion at all career points, from a first undergraduate summer internship to professional awards for senior faculty. They are also critical for obtaining tenure. You need to know who to ask for a letter of recommendation (LOR), and how and when to ask. It is both common and desirable for a letter writer to request that you to draft text for them, or even to write your own letter. This is a great opportunity, but can be intimidating and will be covered in a separate post. Here, I focus on the ask.

Who should you ask? 

The short answer is the most prestigious person you know who likes you and has sufficient expertise to write a good letter. Letters from more senior people carry more weight than those from junior people.

If you are an undergraduate applying for an internship or for graduate school, your letters should all be from professors, ideally ones you have worked with directly, but at minimum from professors whose classes you excelled in. Do not submit a "character reference". They're at best useless and at worst hurt your chances as they make you look like you don't know what you are doing, and don’t understand the goal of the program you are applying to.

If you are a graduate student applying for a fellowship or for a postdoctoral position, you first and foremost need a letter from your PI or primary thesis advisor. We'll cover what to do if this is impossible in another post, but barring extreme situations this is absolutely required. For your other letters you should approach other professors you have collaborated with, focusing on those you are likely to publish with. If that isn't possible, approach PIs you did rotations with. Often these are the same people who end up on your thesis committee, but if not, committee members are also good to ask for letters.

Postdocs need letters from both their postdoc PI and their graduate advisor. From there, focus on collaborators you’ve published with, or with whom you have ongoing collaborations. You should try and find a big name person (major award winner) to be one of your writers. 

Finally, professors up for tenure and or promotion, or for awards, should follow the same logic. You must ensure that you develop and foster a relationship with an established, big name scientist in your field who knows you and your work and who can be a champion letter writer for you. Often your postdoc or grad PI serves this role but not always. In addition, you will want letters from other professors you have collaborated with, as well as leaders in your field that can comment on your work and its impact.

How do you ask?

For anyone you see weekly, you should first ask them verbally, and then follow up later that day with an email. In your verbal ask, mention what you need them to write and when it is due, and say you will send more info by email.

Your next step is to email them (and their admin, if they have one) the below information. 

1. The link or email address they need to submit the letter to, along with the deadline.
2. Specifics of what the writer should emphasize. Sometimes you will want people to focus on the breath of your experience, and other times you will want to focus on an individual topic or discovery. Explicitly tell your writer this info.
3. Attach your CV, and link to any key websites (like the paper your award nomination is based on) if any.
4. Draft a letter and attach the draft to the email. 
5. Attach a short document highlighting any unusual achievements relevant to the purpose of the LOR that your writer may not be aware of.

Notes on Timing

The last step is to make sure your letter writers submit their letters on time. Some awards and application portals send a confirmation email when letters are submitted. If there is no automatic confirmation, ask the writer to let you know when they have submitted the letter. If the writer has an admin, be sure to include them in all correspondence.

Ideally your letters should be requested ASAP. At a minimum, two weeks before they are due. There is no point in waiting to ask for the letter, and it is rude to assume your writer doesn't have other urgent tasks to juggle along with your letter. Send reminders 10 days before the due date, and then again 48 hours before the date. If you have to, send a reminder the morning it is due.

If a letter has no due date, make up one and refer to it as your target submission date. You can always push it back if your writer is struggling to make the date, but keep in mind that nearly everyone is deadline driven, so tasks without deadlines tend not to get done. 

For yourself, track who you have asked for letters in the past, and what the outcome has been. It is much easier for a writer to update and refocus an existing letter, so asking a core set of writers for all of your letters is a good strategy. Also pay attention to feedback. If you ever hear that one of your letters wasn't strong, switch out that writer or offer to draft an updated letter. 

Finding and keeping good letter writers is essential for your success. I hope this post helped you get a handle on how to get started