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If you have a push-up bra with a significant amount of padding, you may not need to add much to fill out the cup. Crumple up some tissues to fill in the gaps, and use tape to hold them in place. Or, fold up a pair of socks for a little extra padding. Since there may be a gap between your chest and the top of the bra cup, these options work best if you’ll be wearing an outfit that conceals your bra. If you want to lightly lift the fleshy parts of your chest, slide a silicone push-up insert into the bottom of your bra cup. Then lift your bust up and over it so it sits on top. Or, if you’d like to add some depth to your chest, place a foam pad on the inside of your bra cup. These can be soft and flexible or stiffer with molded push-up components. Foam inserts are sometimes called “cookies,” while silicone inserts are often called “chicken fillets” or “chicken cutlets.” Breast forms come in a variety of shapes and sizes; some are designed to look like natural breasts with nipples, while others simply create the desired breast shape. Choose a set with an adhesive backing if you want them to stick to your skin for a secure fit. Alternatively, tuck the breast forms into the cups of a standard bra or slide them into a pocket bra for more support.  Try symmetrical breast forms for versatility with any type of bra. Consider wearing an asymmetrical set (i.e. a left and right breast form) if you desire a more natural breast shape.  Choose silicone breast forms with cleavage for a full-looking, exposed bust. These consist of 2 breast forms connected by a silicone chest piece that extends up to your neck. Choose one that matches your skin tone.

Summary:
Stuff your bra with socks or tissues for a small amount of padding. Use foam or silicone inserts inserts to enhance your natural chest. Select a pair of silicone breast forms for a larger bust.