More and more metamaterials and metadevices are developed through a general approach from modeling and design, materials selection and synthesis, fabrication processing and optimization, to validation and certification. Great many design approaches and fabrication processes have been explored for each kind of metamaterials including electromagnetic metamaterials, acoustic metamaterials, mechanical metamaterials, and more others. Moreover, Metamaterials are being applied to the development and construction of many new metadevices throughout the electromagnetic spectrum of the electromagnetic metamaterials, for example. Limitations posed by the electromagnetic metamaterial operational bandwidth and losses can be effectively mitigated through the incorporation of tunable elements into the metadevices. This chapter will give a generic review for the commonly used design approaches and tuning methods as well as conventional fabrication methods and additive manufacturing for various scales of 2D and 3D metamaterials and metadevices.