We encourage you to send a note of thanks to the individual(s) responsible for your attendance. It is particularly helpful to include one or two very specific changes that will be made in the upcoming semester, any anticipated benefit to students, and mention your willingness to offer a workshop on your campus sharing what you learned from this conference.
You may find a printable thank you note here.
Thank you for the support you provided that allowed me to attend the Lilly Conference. I was able to network with colleagues from (list one or two peer or aspiration institutions here). Among many things learned at the conference, I discovered (insert achieved personal conference objective; the following sentence is included as an example) a unique method to assign peer projects that I firmly believe will increase the quality of student work in my senior seminar course and have students to produce more work without greatly increasing the time needed on my part to grade the extra material. Thank you again.