I forgot to pin it, but I totally copied this idea from... somewhere. I'm sure I'll stumble on it again. In the meantime, here's our version.
We picked some lovlies from the yard and pressed them between two layers of contact paper.
And bordered them with some of the kids colored play tape. It's some nice to have play tape, I never have to stress about the kids stealing and wasting my tape. We get ours at Oriental trading. The kids love it and use it all the time for all kinds of interesting projects.
The items aren't dried or really flattened first, and the flower petals have turned out to be a little 'wet' to stay nice in there for long.