im fairly new to 3d modelling and im having trouble in getting the smooth curves and flat surfaces I want on a watch strap ive designed. attached are two picture, the first showing the 3d model in blender (that has shading problems and harsh edges) and a rough drawing of what im aiming to achieve. thank you for your time. Any help or suggestions would be greatly appreciated. Ive already attempted using a subsurface modifier and the strap is already shaded smooth.