I used the 6 Cubby plans and just started tweaking. First was the plan to just do 12 cubbies, then decided to just put in adjustable shelves for aethetic purposes and not having it look too "Boxy" After that decided it would look better with doors too.
as for the shelf on top, I used the cubby bookshelf plans and just made it wider to match the width of the doors and then decided to also make it adjustable shelving as well. (used the kreg shelf pin system.)
Overall turned out pretty good. I am making a even bigger one for my other room.