Simply replace the unfilled areas such as "[]" and "[date]" with your information.
Dear [Meeting attendee's first name],
I wanted to thank you for taking the time to meet with me regarding [reason for meeting]. I feel that we made great headway regarding this, and am looking forward to implementing the items we discussed. I was very happy that you could take so much time to go over the issue with me. I know that you are very busy, and appreciate that you thought the issue important enough for your time.
Should you need any more information from me regarding this issue, please don't hesitate to contact me.
Sincerely,