Well, what I have been doing so far is do full statblocks, with skills, feats and spells chosen. I believe this way they are more useful for when one needs a quick reference, making it easier to swap one or two for more desirable ones for a particular encounter.
Oh, and I probably should note that I haven't counted the skills organically. That is, each category of black dragon has skill points as if it was a unique creature, not a more advanced version. I haven't checked how official WotC sources do skill points for dragons, so I'm not sure if that's how they do the skills. Somebody have a WotC adventure handy, or perhaps one of the Icons?
The feat choices are organic, mostly because I'm too lazy to judge each and every dragon separately, so I'm just adding a feat for every category to the list of the previous category.
Here's an example dragon, suggestions for better feat and spell choices are welcome.