An important part of a uniform concept for exhibits: The arrangement of individual objects, such as tables, charts, and graphs, is as strictly defined as the position of the organizational elements, for example titles and page numbers.

Three example grid concepts for the combination of Excel-PowerPoint are presented in the following, the complete Excel file can be downloaded here.

All DOWNLOADS ON THIS SITE ARE IN GERMAN.

Grid for the ROI-Tree
The grid used here matches the "ROI-Tree" Excel solution as found in the section Example Exhibits.
Excel download here
PowerPoint download here
PDF download here

10x10 Grid

Here is a 10x10 grid set up within the interior frame of the picture. Many graphic designers prefer a 12x12 grid due to the better level of divisibility by 2, 3, 4, and 6, please see below.
Excel download here
PowerPoint download here
PDF download here

12x12 Grid outside
Here is a 12x12 grid set up x- and y-directions and which divides the exterior frame.
Excel download here
PowerPoint download here
PDF download here

4x4 Pictures
On the left is an example  for the grid in a "Multi-chart exhibit." What is important for working with Excel: precise positioning on the cell corners with which the size of the entire exhibit can be changed accurately down to the last pixel!
Excel download here
PowerPoint download here
PDF download here