The aim of this study was to investigate the effect of hydroxypropyl methylcellulose (HPMC), as the basic film-forming material, on the properties of edible films and coatings and, on the other hand, to examine the addition of cellulose nanocrystals (CNC) or/and cyclodextrin (CD) to the HPMC films in various proportions. The investigation of the HPMC-CNC-CD triple combination was executed in the context of exploring innovative material combinations and enriching the existing literature in this field. Specifically, not only the properties of the final formed films and coatings were thoroughly investigated, but also the properties of the solutions from which they were formed. Thus, the addition of both CNC and CD improved most of the properties of the HPMC-based films. Specifically, with CNC as well as CD, oxygen and water vapor permeability decreased, while transparency and heterogeneity increased. Beyond that, CNC led to more stable structures with enhanced mechanical properties, whereas CD led to improved optical properties. Finally, the minimum viscosity value required to form a homogenous HPMC-CNC-CD film was determined at 2.94 mPa·s which corresponds to proportions of 50–30-20.