Of all the components in your job search, advice on thank you notes is likely the most ever-shifting and varied from one person to the next.  It is important to check with CDO staff for individualized advice for particular employers and situations.  When in doubt, bear in mind that you are unlikely to injure your employment chances with a heartfelt thank you in any well-written and error-free form. 
Screening Interviews
There is typically no need to write a thank you note after an initial screening interview.  However, if you elect to send one, you should do so within 24 hours, and you should keep it brief.  Email is the best form for such a note, and the subject line should be simply “Thank You.”
Callbacks and Informational Meetings
For law firms that do a lot of callback interviews during OCI season, especially the larger firms, there is no need to send thank you notes to everyone you met.  If there is someone at the firm who particularly helped you get the callback, or if there is a unique reason for you to follow up with someone, then a thank you note is appropriate.  You might also consider writing one thank you note to the hiring partner or recruiting coordinator, and ask that person to pass along your appreciation to the others with whom you met. 
For smaller law firms, in-house legal departments and public interest employers, especially employers that do not hire law students on a regular basis, thank you notes after callbacks may be more helpful.  This is where you have to exercise your judgment, based on your experience during the interview.  
If someone takes the time to meet with you to give you career advice, a thank you note is almost always a good idea.  
If you choose to send a thank you note for any of these instances, either email or a handwritten note is fine.  In either form, remember to:
  • Express your appreciation for the interviewer’s or employer’s interest in you, or for the person’s time, and for their hospitality during your visit.
  • Mention something unique that you talked about during the interview or that occurred during the interview day, so the recipient of the note knows that you personalized it.  If you write one form of note and send the same language to everyone at the employer, you will likely do more harm than good.
  • Indicate that you remain interested in the position.
Note Cards
If you write handwritten notes, purchase cards that are tasteful and very plain.  They should be either blank or monogrammed with your initials or name.  They should be white or ivory.  You can choose from an array of budget options and still have an appropriate card.
Regardless of the form of note, proofread it at least twice.  A thank you note with a typo or other error can be very detrimental to your efforts with that employer.