OK, this doesn't have to be a ranunculus, it could be any poofy flower, but ranunculus does actually come in this color so I'm calling this a ranunculus. Also, ranunculus is fun to say.
This is inspired by the flower in Sew Subversive (I think) but its poofier.
1. Cut several circles out of woven fabric; I used about ten. First circle should be about 20% bigger than you want the width of the final flower to be, and then subsequent circles should descend gradually in size.
2. Cut the edges of the circles with scalloped scissors or pinking shears.
3. Cut a small circle out of the middle of each circle of fabric, each cut should be the same size.
4. Baste around the edge of the inner circle of each piece of fabric, then pull the thread tight so that the fabric scrunches up evenly.
5. Sew all the pieces together and attach a fabric covered button to the center (for info on making a fabric covered button, please see this tut)
These work great as decorative accents or brooches, and are fun stash-busters.