Handwrite the note to stand out and reference the (correctly spelled) names of all people you interviewed with. Also, mention the key projects or priorities that were emphasized in the interview. Usually, these are the priorities the incumbent will be hired to work on. Remind the hiring manager of your fit, enthusiasm, and ability to hit the ground running.
Try to select your top three qualifications in a nutshell and remind them of why you are the best candidate for the job. Now is not the time to be humble. Lastly, ask for the job, even if it's something like, "I hope we can move forward together soon with this opportunity."