Actually, I don't really like this suggestion as it only works if all
your content is on one layer.
If you have multiple layers in a project, you get in lots of trouble if
you follow this path.
On 2013-11-13 20:29, Chris Tooley wrote:
I would group all your items temporarily (to make sure they stay
positioned relative to each other), then modify the document settings
to be square, then center the grouped items on the square page
vertically and horizontally.