So, I do realize that Christmas is already over, I just haven't gotten aroynd to posting this yet. I have no excuses for not blogging so much, other than Instagram (by_moe) taking over my life :p
Anyway: what you need is a styrofoam ball, felt and pins.
Cut circles about 8cm in diameter, then cut those into spirals.
Roll the spirals up to a rose, starting from the outer end in to the middle, and then stick the middle end under the rose. Put a pin through the middle of the entire rose and pin it to the ball. And repeat until the ball is fully covered.
A tip for the string: tie it first around the ball before you pin the whole thing, this will ensure that the string wont fall off. I've used a hemp string (love those), but you can use just about anything you want.