First thing: let's differentiate between "layouts" and "presets" in MIDI Designer. Layouts are made up of banks and pages. You can save them, load them, and send them via email.
Presets, on the other hand, represent values on all your controls. For instance: in Preset 1, you've got all the controls set to 20, and in Preset 2, they're all set to 75 (simple example). One of our users suggested that we call presets "Snapshots," which is also a good idea.
See the FAQ about this here.
So you don't move to a blank preset. You can only save the current where-the-controls-are-at to a preset.
With layouts, you might want to move to a new one. Do this by first making sure you save your work (or mail it, which is a great way to save). Then you can move to a new layout by doing Config -> Actions->Reset UI (poorly named, thinking about it now).