I believe in two principles: primarily clinical experience and, secondly, exams that force students to learn.
THere is no substitute for clinical practice with real patients. I have a short attention span with "innovative" "technology driven" "concepts" designed to "enhance" the "learning environment". Equally troublesome are the fake patients used with the step II CS and OSCE's. They do not react like normal patients.
Grand rounds presentations that supplement clinical experiences I find to be the most helpful. Specifically, experienced clinicians talking through how they approach clinical problems for residents and med students who have a little experience under their belt for reference. But, these presentations take time to prepare, which is why good ones can be few and far between. In short, the clinical experience becomes the basis of lifelong learning rather than the memorization which is the norm as undergrads and MS1-2.
For the younger med students, learning the basic principles of physical diagnosis and then practice, practice, practice with real patients. In the first two years the students can go along with the Medicine teams on rounds 1-2/week before lectures so that they see the reality of medicine and a reference point in reality for what they are studying. As for the lectures, I actually found them useful, but always took something to study in case the lecture was no good. No matter what I still needed to understand the material.
A word on exams: preparing good exams that prepare for USMLE and shelf exams is time consuming, but is very important in order to hold the student accountable for actually studying the material by whatever methods works for them.