Sorry if these are repeats:
A magnesium (concrete) floater works great to hold a long ruler in place for rotary cutting. They are surprisingly light weight and keep the ruler much more accurate with less pressure.
A plastic pencil box with a snap lid on it ($1.00 at Wal-Mart - ?) is the perfect size to store a 45mm rotary cutter.
I use pant hangers with clips to hang cutting mats since someone said the mats needed to be stored flat/straight and not leaning up against something.