Cut a piece of cardboard to the shape and size that will fit around your beverage.
Make a fabric that is slightly larger than the piece you made in step 1.
Trace your cardboard piece onto your fabric.
Cut it out.
Place a button or hook or loop fastener on the ends of your sleeve. If you want to attach a button, make sure to cut a slit on the opposite side of your sleeve that is big enough so the button will fit through.
Cut out other embellishments or designs with Duck Tape®.
Place your design(s) on the piece you made in step 5.