I typically just put the fat facing the heat. As I never have really had a heat source from up top that generally means fat side down. I also usually trim my briskets down of most fat in order to get more bark on the meat, and I also like making beef tallow with it for frying purposes.
In my years of BBQ I have never smoked just a flat, as I REALLY like the point. The flat is always going to look dryer than the point will, but the point will look REALLY freaking juicy.
The Life of the Knife is Ended By! The Wife.