I've been playing. Saw this on the DC gallery and thought it was very pretty so I had a go. The buttercups were made using a woodware punch with 6 petals (I didn't have one with 5) and the stamens with a Nellie Snellen punch. 3 layers on each buttercup.
The daisies are an old daisy punch and Cardcraft Candy for the centre (painted with promarkers for the colour)