I asked my family doc if he knew anyone I could shadow, and he volunteered himself. I ended up shadowing him one day a week for about 6 months, and I absolutely loved it. I was lucky-- this doc is a preceptor for UNC and Duke's first year med students, so he did the same program with me that he does with them (and he wrote me a great LOR). He told other docs that I was shadowing him, and they asked me if I wanted to shadow them!! 😱 Unfortunately, I didn't have the time to take them up on their offer, but it was so incredibly nice!!
What I'm trying to say is that in my experience, most docs don't mind having people shadow them. If they are unavailable/unwilling to have you shadow them, then they probably know a doc who can help you out. I liked shadowing for the time that I did-- I got to see some of the same patients several times and it was great to see their progression. Set up a schedule that will suit your needs and the doc you're shadowing's schedule. It was a great experience for me. 🙂