Fit and comfort are the first considerations. Accurate measurements of the chest circumference and bra cup size are needed for a proper fit. A well-fitted prosthesis should feel secure but not constricting. It should fit close to the chest and hug the chest contours. The weight of the prosthesis should be as light as possible. For a larger breast prosthesis, some extra weight should be added in the bottom of the prosthesis where it would be naturally. Since the prosthesis is held in place by the bra straps, the fit of a bra is extremely important. The prosthesis should be made from hypoallergenic and breathable materials to prevent skin irritation and allow for comfortable wear, especially against sensitive skin. Materials should be durable enough to withstand daily wear and tear, including exposure to water (if the wearer wishes to swim) and routine cleaning. The prosthesis should closely resemble the shape, size, and color of the natural breast, including features like skin tone and areola/nipple detail. Options for customization, such as different shapes can help meet individual preferences and body types. The design should work well with various types of bras both pocketed and non-pocketed, ensuring a secure fit and adequate support for the unaffected breast. For active individuals, the prosthesis may need to accommodate sports or high-movement activities. The prosthesis should provide cushioning and protection for the chest. The prosthesis should distribute weight evenly across the chest. The prosthesis should not be so heavy that it pulls away from the chest when the wearer bends over. A prosthesis that is too heavy will cause strain on the shoulders and back and promote poor posture. The prosthesis should be easy to clean and maintain, with clear instructions on how to do so to ensure longevity and hygiene. Designs should allow for adjustments in size or fit. The wearer’s body will change over time due to weight fluctuations and there should be a way to accommodate these changes without having to purchase a new prosthesis. Collaborating with breast prosthesis wearers, experienced fitters and healthcare professionals can ensure that the design meets medical needs and personal preferences. Providing information about different types of prostheses and their uses can empower individuals to make informed choices. A design that provides comfort, enhances self-image and confidence can play a significant role in emotional well-being. The cost of prostheses can vary widely. The design should provide quality without being prohibitively expensive. The reimbursement rate of provincial health programs, insurance companies and assistance programs should be considered. Ensure that the prosthesis can be easily accessed and fitted, through healthcare providers, online resources or local shops. When designing an external breast prosthesis, a holistic approach that considers comfort, aesthetics, functionality, and emotional well-being is essential.