Ashley from Make It and Love It shares the how-t0 on her blog for embellishing a t-shirt with these folded and layered fabric flowers. Each flower is made from 6 circles of knit fabric that she has folded and stitched together. To get the flowers the same color as the t-shirt, buy two shirts: one to embellish and one to cut up into the circles. Go to the tutorial.
[photo from Make It and Love It]