Take three of the droplet shaped beads from your black bead mix and thread them each onto a headpin.
Trim and loop the top of the headpins. 
Attach these two three of the holes at the base of the skull charm using jumprings. 

Cut two lengths of illusion cord measuring approx. 14-15".
Thread a crimp bead onto each of the strands.
Thread one end of each of the cords through a filigree hole near the top of the skull charm.
Go back through the crimp bead leaving a 1" tail and squash the crimp bead quite close to the skull charm, allowing for some movement. 

Thread a mixture of black glass beads onto each of the cords, remember to thread your first beads over the tail of illusion cord to hide it. 

Finish your necklace by threading another crimp bead onto the end of the cord. Thread through a jumpring and back through the crimp bead and into your necklace. 
Squash the crimp bead to secure on the jumpring. 
Repeat this on the other strand of your necklace. 

To one jumpring attach a lobster clasp.
To the other jumpring attach a second jumpring.