The number of students, the degree of flexibility you wish to give students for their study, the subject, the learning outcomes and the assessment being just a few. I think the golden rule, however is never to promise more than you can deliver. A simple surgery and e-mail help line which works is far more acceptable to students than the most elaborate and sophisticated mutiple media scheme which fails to deliver. My own preference is for structured workshops giving students the opportunity to apply that which they have learned, discuss points of concern or misunderstanding and bring their own researched or experiential information into a group exercise. Each student may have fewer, more effective sessions, but the staff work load can remain the same.
Various models exist.
I have learned a lot from my experiences. Both courses give our academic staff the opportunity to work together to produce and evaluate materials for their own delivery with access to support and help from Learning Development Services staff and selected experts. BUT it is also very rewarding, very effective if well done and once you have finished a piece you can customise, update, expand, select etc. without ever having to start again. However in my experience they do better in assessments because they are not relying solely on memory. Please let me know.