Measure the chain to your wrist (or however long you need it to be). When you have the appropriate length, attach the clasp with jump rings.

Select a number of buttons for your bracelet. I chose smallish buttons in pink, purple and yellow. If you like bulkier jewellery, larger buttons might work better.

Using jump rings, attach the buttons at fairly regular intervals on the chain. I used a colour pattern and regular intervals first for the larger buttons, then went bad and added in the smaller buttons between to fill it out.
Keep adding until you are satisfied with the size.

Tada! Bracelet!