Getting a custom costume can be a expensive. So, I have complied a list of where I tend to buy costume supplies. Please note, I have not been paid to put any items on this list, nor do I guarantee these products. All of the vendors on this list can be found online.
For my purposes, I do not buy Swaroski. I don't feel like the shine is worth the extra money.
Glass Rhinestones- Aliexpress
Sew on Rhinestones- Ebay, Gigi Dilsah, Aliexpress
Resin Rhinestones- Aliexpress
Fabric and costume base supplies:
Chiffon- Stylish Fabric
Bra cups- I tend to make my own at this point, but I love Dina cups. I would order a few sizes up.
Belt base- Thick felt interfacing. This can easily be found at most craft stores. I then cover it with my fabric.
Pins- I use quilt clips as opposed to pins.
Used Costumes- Facebook swap meets, I don't have a preferred group.
Rhinestone Necklaces- Raining Rhinestones with Joy
Ballroom Dance Shoes- Light in the Box (order a few months ahead of time, shipping can be long)