Format of letter of thanks to a professional for training conducted?

Format of letter of thanks to a professional for conducting a training?

Format of letter of thanks to a professional for conducting a training?

A brief letter thanking him for the educational experience, the detail involved, any enlightening experience that occurred, if the training was 'keyed and focused' as expected, her/his delivery process, any materials they provided, and any personal insight that occurred for you personally.

Stringer