One of the major improvements, in the upcoming LibreOffice 5.3 (scheduled to release on January 30, 2017), is the Page Deck for Writer. The deck hosts four panels - Page Format Panel, Page Style Panel, Page Header Panel, and the Page Footer Panel - to bring you the most commonly used page properties. This post aims to describe all the aforementioned panels and the features they provide.
The entire enhancement report can be found here. I myself have been working on this, with the help of my mentors - bubli (Katarina Behrens), and jay (Yousuf Philips).
Page Format Panel
Size dropdown to easily select standard page sizes.
Width and Height spinboxes to customize page size.
Orientation listbox to choose between Portrait and Landscape mode.
Margins listbox to select preset page margins. Available presets are -