Whether you're making your own pendant or turning your favorite finds into a necklace, you may run into one small problem -- how to attach the pendant to the chain. If you can't tie, wire or loop the pendant onto the necklace, purchase a bail that suits the style of the pendant. Be prepared, though; some bails require epoxy to keep the pendant intact.
If your pendant has a small hole in the top -- or if it's made from an item that can be drilled with a narrow bit -- a screw-style bail is perfect for your project. The simplest version looks a bit like a screw-eye, with a threaded end and a loop at the top. Fancier versions add a more elegant framework instead of a simple hooked loop. Insert the screw end into the top of the pendant and twist to secure it in place. If you're concerned about it falling out, add a drop of epoxy to the tip of the screw end before inserting it into the pendant.
A donut bail connects donut- or washer-style pendants to a necklace. These bails feature a front and back that can be pulled apart slightly so you can slide the pendant between its jaws. Press the bail closed to secure the pendant. To attach it to a necklace, run a string or chain through the top of the bail, or add a jump ring to the top of the bail; then attach the jump ring to the necklace. This style of bail is available in a vast array of sizes, styles and finishes, as are bails in general.
Many bails require an epoxy to hold the pendant in place, but the advantage to this style is that just about any item with at least one flat surface can be used as a pendant. Some feature a decorative embellishment such as a leaf shape on both the front and back and fold down over the top of the pendant, while others have a more plain metal portion that hides behind the back of the pendant with nothing but a loop visible above the pendant. A strong epoxy designed for jewelry attaches these styles of bails. Bell caps work in similar fashion, folding down over the top of a pendant that may not be flat, such as a gemstone.
If your pendant has a hole drilled from top to bottom, it's the perfect candidate for a pin bail. Pin bails are like head pins: a post with a wide, flat end. The other end either has a hole in it or a removable loop at the top or bottom, for swapping out pendants or beads any time you like. Make your own pin bail by putting a head pin up through the bottom of the pendant, then bending the other end into a loop using your favorite jewelry pliers.
Turn any item into a pendant by twisting and wrapping wire around it, creating a loop with the wire at the top. Use a thin craft wire or a flat wire designed specifically for wire-wrapping jewelry.