You will need: some large stones, a few flowers, a large, heavy book and baking paper (or a flower press), pva glue or modge podge, a paint brush. A sharpie if you want to write on the stone.
Collect a few flowers. If they are tiny, take a stem with a few on, if they are larger flowers, collect individual ones. Once inside, take your baking paper and fold it in half.place the flowers flat facing down in between the baking paper and place the book on top of them. Leave them for at least an hour (over night is also fine!).
You can either leave your stones natural now or paint them white whilst you are waiting. We prefer ours natural, other people like white painted stones as the flowers are clearer. It doesn't matter which you'd rather.
Take the flowers out of the book. Get your PVA glue and mix it with a little water (about 1/4 water to 3/4 PVA). Now take your stones and paint the glue onto them. Stick the flower down onto the stone, with the colour facing upwards. Make sure you're happy with its location and paint over it again with the glue, until it is entirely covered. Put to one side to dry.
It should now be ok to put outside, but if you want real longevity, you may want to paint it with varnish over the top. Now you can pop them outside where ever you want.