Simply replace the unfilled areas such as "" and "[date]" with your information.
Dear [Company Representative or Hiring Manager],
It was a pleasure meeting with you today regarding the [Position Title] position, an opportunity I find quite exciting. As we discussed, my qualifications very closely match the requirements you have for the position. My [relevant experience discussed in interview] experience would greatly benefit your [team/company]. In addition, my [soft skill], [additional soft skill], and professional drive are traits that you emphasized were of value to your company.
If I can be of further assistance in the decision process, please feel free to email me at [email address] or give me a call at [phone number]. I look forward to hearing from you shortly. Thank you for your attention.