We made flowers as shown in this tutorial on Family Fun.com, Flower Pins and clips . Then we put a green pipecleaner through the gap of the center and petals and through the back and twisted. See the ones on the right?
I made the girls small (4" by 8") sketchbooks, and we went outside and drew flowers from our yard and the bouquets from my hospital visit. I asked the girls questions about each flower (what shape are the petals? How many rows of petals are there? What shape is the center? what color is it?) to guide their drawing.
For more flower ideas, check out this Flower Garden Party from Make and Takes