If you have a dry mount press, or access to one, dry mounting will keep your prints the flattest (see the 1st four pages of this PDF: http://www.hotpress.co.uk/Hints.pdf). Sans a press, you need to get your prints as flat as possible (not a problem if we are talking RC, more trouble if fibre) and use either hinges made from archival tape or pre-made corner mounts as described in the links above.

Cheers, Bob.