There are so many jobs for clear elastic in lingerie sewing. You can add it at the top of the cup under a galloon edge. You can use it to ruche the center of a bralette or the back of undies. You can use it as a supplemental elastic behind a soft lace to make sure that there is enough elasticity for the job you need to have done.
Here's a helpful article to get you started sewing with clear elastic.
Please order by the yard.