Accurate characterization of shale formations still faces some key challenges due to their complex matrix heterogeneity and fabric anisotropy. Predicting the mechanical behavior of shales using geochemical proxies has generated promising provisional results. However, challenges including compositional variation and data resolution need to be overcome. Imaging techniques such as correlative microscopy and X-ray CT are effective at characterizing multi-scale shale properties. However, the integration of both data and sample preparation techniques is cumbersome and requires improvement and simplification. Pore-structure characterization determined using mercury intrusion and nuclear magnetic resonance techniques needs to be better calibrated to resolve disparities due to fundamental differences in the measurement techniques. Geomechanical property prediction is currently constrained by a proper micromechanical upscaling models. For better representation of actual shale microstructure, further advancements in digital rock modelling and image-based simulations are needed. To further improve the evaluation and development of shale reservoirs, future research should be aimed at bridging these gaps through the advancement of more integrated techniques and interdisciplinary approaches.