Twisted tubular herringbone is one of my favorite bead patterns to work with, it's relatively simple and gives nice results.  For this necklace, I used size 6/0 seed beads and chose a color pallet of turquoise, amber, gold and white.  I used a somewhat randomized approach to add beads to the necklace that gave the look a bit of controlled chaos.  I also used shiny, transparent and metallic beads for a variety of textures.