In this study, the focus is on techniques for playing contemporary music on the viola and other bowed string instruments. These techniques include playing overpressure, some percussion techniques, special pizzicato and left-hand pizzicato techniques, different contact point techniques, various harmonic techniques such as Effleuré, multiphones and subharmonics, and trills. In order to effectively execute these techniques, it is important to experiment and practice them in various ways. To properly execute percussion techniques, for instance, it is suggested to seek guidance from percussionists and for pizzicato techniques double bass players or guitarists. For practicing part, this thesis should be a help for players struggling with the extended techniques. The use of these techniques is discussed with the goal of practicing them to achieve the highest level of performance possible.