To support K-8 educators in integrating computational thinking (CT) into basic digital education (BDE), as introduced in Austria in 2018, we present design principles for a practical handbook. Teachers without a background in computer science (CS) may hesitate to teach CT and prioritize media and computer literacy aspects of BDE, potentially neglecting CT in the revised 2022 curriculum. To overcome this, we iteratively developed design principles for a handbook with three practical learning environments (LEs) employing physical computing with a single-board computer. The LEs embrace the constructionist approach and emphasize experiential learning to support intrinsic learning of CS/CT concepts. Complementary, an Open Educational Resource (OER) textbook is available that is aligned with the 5E instructional model and promotes self-directed, inquiry-based learning. This makes CS/CT more accessible to both teachers and students, regardless of their CS knowledge. Following these principl es, they are systematically guided to gain confidence in applying CT in the classroom. Further research will evaluate and refine the design principles on a larger scale, contributing to the development of a comprehensive handbook. Ensuring accessibility to fundamental CT skills in K-8 education is crucial for the successful implementation of basic digital education (BDE).