HF-guiding structures connect the components of a system or supply them with necessary power. Various techniques have been developed to design guiding structures and obtain the best performance (minimum attenuation and dispersion). However, technical implementation depends on their application and frequency. In this article, various processes to implement guides in planar and multilayer technologies are presented. Several aspects related to computer-aided design are then addressed, namely the scattering matrix of a multi-access device and the procedure to characterise several connected elements. Performance criteria such as attenuation and power-handling capacity of several guiding structures are discussed. Finally, some applications and future developments are presented.