Actually, I think this is a good idea. As a former high school teacher that had to write LORs for seniors going to college - it got tough writing those damned things without sounding like I was saying the same thing all the time.
First, it goes without saying that you need to give this doc a copy of your CV/Resume. Most likely, it has things on it that he/she doesn't know about you.
Second, sit down and think of things that you HOPE he saw in you and your performance....but you aren't sure he saw. For example, you could put:
1). I am hoping you found my enthusiasm for this field to be extrordinary (sp??).
2). One of my goals for this rotation was to display my ability to be a team player, while at the same time showing vigorous individual motivation.
3). It was my intention to illustrate to you my desire to be a self-learner, as well as someone who is pliable enough to be educated in many different ways.
I don't know...but these sound good. Don't go overboard and say something to the effect of "I want you to write on my LOR that I am the best student you've ever seen" - that would be suicide. Just think about what you honestly wanted to display to this doc....and tell him so. One good thing about this is that if you didn't do what you are writing were your intentions...it opens up the door for a very good conversation where he can say "hey, I didn't think you showed you were a very good self learner...her'e's what I was looking for in that respect" - or whatever. Many students have misconceptions of how they are perceived..and never are told so. Bottom line - Just be honest and point out your good points. You can also say something a little 'negative' - and then go on to say how you've improved:
4). I would like for my letter to mention how I was somewhat passive in my education regarding **ENT**, but that I quickly became an agressive and active learner.
Good luck - hope this helps a bit. - you may also want to ask that he write something about how you would be a hard-working, valuable asset to any residency program. One of my docs wrote in my LOR "She is a pliable individual, capable of being educated in many different ways. She will be an asset to any program."
I thought that said alot...programs don't want residents who already know everything (or think they do).
Again - good luck.