Having worried about this just like you prior to my intern year, I can say that I think this is one of those things that every incoming intern worries about that really turns out to be nothing to worry about. Just like finding a "strategy" for making your third year medical school schedule, this is just as ambiguous. Someone will argue the benefits of making your schedule each and every way possible, but it really isn't worth worrying about it, with the exception of a few things.
-Try to anticipate important events in your life (vacations, weddings, etc) and try to schedule call-free months or vacation during that time
-If you have a thought about what you may want to do for fellowship, especially those with matches that are earlier in your second year of residency (eg, cards, honc, allergy, and a few others) try and do electives in these your intern year if your program has elective time allotted in your intern year.
But scheduling wards vs nicu and trying to figure out which one to do early vs late, it really is pointless to waste your time strategizing since each service will be difficult regardless of your previous experience. I did a NICU sub-I my 4th year of med school and scheduled it early my intern year thinking I would have an easier time. I was wrong. It was still very difficult and I really didnt think I had too much of an advantage over my fellow interns.
So don't worry too much about this, and enjoy the short time you have before starting intern year. Intern year will be the most fun you will never want to have again!