It's something I am working on this year in case I need to re-apply. Although, the volunteer program I am in provided some sort of shadowing if you will along with other duties. I was able to step in the patient room and observe and sometimes perform some tasks such as take blood pressure, look in patients' ears and mouth. I'm in the ER so I've seen a plethora of different cases. I've seen level 1 traumas and sometimes even got to assist e.g. flip patients over, perform CPR, etc. I feel I had my share of clinical exposure and understanding of medicine from the perspective of a doctor, nurse, and admin staff as far as the ER goes and a few departments such as cardio. I did get a LOR from the director of the program. The reason I did not shadow is because my pre-med adviser approved the type of clinical exposure I was getting and some of my pre-med friends said they shadowed and didn't get much, if any patient contact.
Now that I am in my gap year, it's something I will try to explore.