For each bracelet, cut a length of elastic twice the length of your wrist measurement.
This is so you have enough elastic to work with.

Choose the pearl beads you want on your bracelets and thread them onto your elastic.
Once you are happy that you have enough beads to snuggly fit your wrist, thread on one of your rose gold charm carriers. Secure your bracelet with a surgeons knot (see image). You may wish to add a drop of glue or clear nail polish to secure the knot further.
Trim your tails and hide the knot inside your charm carrier bead.

Once you are happy your bracelet is secure and the knot won't come apart, attach your chosen charm using a rose gold jumpring.
If you are using a Swarovski crystal chaton, add a drop of glue into your charm setting and carefully place your crystal in.
Attach this to your charm carrier using a rose gold jumpring.