This isn't my design, I just ran across it on Thingiverse. 3-D printed organizer for 50g round tins. The design incorporates a recess in the bottom to glue in a magnet if you wish to keep the tray attached to the tin. I haven't printed one yet but will give it a try.
Link to the Thingiverse page: Tobacco Tin Divider
Link to the Thingiverse page: Tobacco Tin Divider