To assist users in generating new layouts based on an existing layout, Adobe added the Alternate Layout feature, which creates a duplicate of your original layout, optionally with a new page size and orientation. When exporting your project for a .folio file for Adobe’s Digital Publishing Suite—for publishing to devices like the iPad—both the horizontal and vertical layouts are automatically included.
InDesign CS6's Liquid Layout feature assists users in repurposing layouts for different devices. And, since every project is different, Adobe included multiple ways to reformat pages. Sometimes, all you need is a simple Scale technique for resizing everything on the page in the same way. Other times, you don’t want to scale page objects, but rather re-center them on the newly sized page.
However, designers will want even more control than that, which InDesign CS6 provides by way of object-based layout adjustments. If you choose the object-based Liquid Layout approach or rule, each object you hover your mouse over will display little handles that you can use to pin it to one or more edges of the page. Then, when you resize the page, the object stays the same distance from the edge of the new page as the original. All the other objects on the page will float into new positions as the page is resized. Adobe helpfully lets you pin the object by either clicking the pins attached to the object, or by clicking checkboxes in the new Liquid Layout panel. When working with complicated layouts, the checkboxes can be easier to click than the pins.
Other Liquid Layout techniques include: Special guides to control the positioning of entire columns or rows of frames in long, rigidly structured documents and the Controlled by Master function in which pages are adjusted according tothe Liquid Layout rule assigned to their Master page.
The Liquid Layout approach is just a starting point—you’ll still need to adjust objects manually after the conversion. In my testing of all of the Liquid Layout rules, none of them gave me anything close to a perfect result. Thankfully, InDesign can show you a live preview of how your objects will change. Just use the improved Page tool to drag the corner of your page to its new size and watch as objects move and resize.