Cut a length of wire (gauge 20 or 22) and make a loop in the end with
round-nosed pliers. Put some beads on the wire and then cut it, leaving
enough wire for the finishing loop. I often use metal "spacer" beads
which blend in with the wire but provide valuable spacing to the design.
Step 2: Add Some Chain
You can attach a length of chain with a jump ring or just slip it directly on the loop you made in step 1.
Step 3: Add a Clasp
Use jump rings to attach each part of the clasp to the ends of the chain.
Voila!
And here's the basic bead-and-chain necklace. You can easily experiment by
varing the number of beads and the length of chain in between each bead.