New apparatuses and methods for their design and use are disclosed that can be used to assist a surgeon in placing a guide pin during hip surgery. Specifically, a hip surgery method is disclosed in which an image of a patient's femur can be obtained and used to design and prepare a mold that contains an aperture for guiding a drill at the desired location and angle. During surgery the mold can be quickly and accurately positioned on the exposed femur head. Then, a drill bit can be inserted through the aperture and an opening for a pin can be drilled into the femur head. The mold can have a unique contoured surface adapted to fit to the femur head in a single unique position such that the opening is made in a unique desired position. The apparatuses and methods facilitate faster, more accurate surgery and are less invasive.