This technique, from Make It With Me, makes small cupped flowers in groups, like little bouquets of tulips. With a slightly different edge and colour on the flowers you could make other cluster flowers such as hydrangea or lilac. I use various old paintbrush ends for my own flower sculpting although I tend to not use cornstarch or other release agent since most clay will twist off the surfaces easily enough. If you use cornstarch to your clay it makes the tool come away easily but it also makes it difficult for other items to stick to the spot if you need to add to it later.
Check out this book on how to make polymer clay flowers.