You can download the pattern for the collar here!
To begin start crocheting circles in different sizes. This is quite fun to do!
Print out the collar (PDF provided) and use it as a guideline to arrange the crocheted circles together (don't worry if it doesn't fit exactly). When you are happy with the arrangement stitch everything together.
When finished stitching the collar the next step is to create fastening. The easiest (and prettiest) is to stitch a button or a bead on the right side and crochet the loop (using chain stitch) on the left side.
I hope you will like it :)