First you measure the head of the one who will be carrying the "Krans".
Take some thick wire and form it into a circle as large as the measurement say it will need to be.
We use a tape and put it on the wire, so that the wire is completely covered, I don't now it's name but it can for sure be bought in any flower shop.
It's green and it makes it easier to attach the flowers and leafs - if you only use wire, it will be too slippery and the flowers will move around.
Choose whatever flowers and leaves you like.
Make a whole lot of tiny bouquets where the stalks should be about 4 cm.
Then you use some thinner wire to bind them to the circle of thicker wire.