When it comes to Easter projects, nothing could be simpler than to start with the egg. Whether real ones or the plastic treat-holder type, eggs are lots of fun to decorate & (despite the curved surface) are not too difficult to stamp on.
Now's the time to use those small stamps many of us have. No small stamps? 'Sok. Pencil erasers make great stamps, too. AND the erasers can also be used to 'mount' those tiny stamps. Just swipe the eraser with a gluestick & it will hold your stamp.
The shell of real eggs is very good at accepting lots of different media--dyes, inks, paints, crayons, etc.
With the plastic ones, you may have to test to see what works on them. If you spray them with a matte finish before stamping they will usually accept even dye inks.
Want to use your larger stamps? Fine! Try placing the stamp--die up--on a firm work surface. Load it & roll the egg over the image. Or... Stamp your images on tissue paper & glue them to the shell.