I used my almost forgotten seaside themed stickers from K&Co to make these magnets:
They were pretty easy to make - the size was almost the same as the clear glass pebbles I adhered them to. The pebbles are not perfect circles, so I had to snip from the paper here and there. If you would like to make some too - here is a tutorial.
I'm planning to use them as part of a teacher gift, so I created the background for them. Stamped the map background image from Flourishes onto light green paper from Basic Gray, sponged the edges with distress ink and applied some K&Co rub ones. Then I just adhered 4 little metal washers with ScoreTape and snapped the magnets in place.