Plant fibers find wide application in various fields that demand specific parameters of fiber quality. To develop approaches for the improvement of yield and quality of bast fibers, the knowledge of the fiber developmental stages and of the key molecular players that are responsible for a certain parameter, are vitally important. In the present review the key stages of fiber development, such as initiation, intrusive growth, and formation of thickened cell wall layers (secondary and tertiary cell walls) are considered, as well as the impact of each of these stages on the final parameters of fiber yield and quality. The problems and perspectives of crop quality regulation are discussed.