My own design approach is simple. It is creating a main Form in mfPage mode with top menus. I use Modal Forms for data input and other stuff.
Other strategy can be a UniTreeView aligned on left with Pages, Frames and Tabs on right similar to our MegaDemo.
While uniGUI allows designing complex UI, I always prefer the simplest way to achieve best functionality. Complex UI can slow down browser and take a long time to load on slow connections.