I've seen this kind of headband all over the place lately and have been itching to make my own. So I did! It was super duper easy and really inexpensive. Here's what I did:
First what you will need is:
A bouquet of fake flowers of your choice (roses, daisies, ect.)
Some matching ribbon
Cut your ribbon to desired length (circumference of your head plus enough extra to tie a bow).
Pull all your flowers off their stems.
Pull the petal part (if any) off the flower.
And cut the stem so that it doesn't poke out.
Put a dab of hot glue on.
And stick it on your ribbon. Note: I started with one in the middle and then worked my way out. Also, place them close together so that when it bends around your head, the ribbon doesn't show through.