Powders are used in various industries, including paints, pharmaceuticals, and food, where their flow behaviour is crucial. It is vital to understand powder flow to avoid blockages and unreliable flow patterns out of hoppers. Shear cells are the most effective method for determining powder flowability under moderate stress, with applications in silos and hoppers. However, processes like powder dosing in capsules and dry powder inhalers involve low consolidation stresses (≤ 1 kPa), where shear testing for unconfined yield strength faces inconsistencies. Ball indentation (BI) has emerged as a solution for low-stress flowability assessment, estimating unconfined yield strength indirectly by measuring hardness. However, BI requires determining the powder's constraint factor, which represents the added resistance caused by the elastically deforming region surrounding the plastically deforming indentation zone. This work aims to optimise BI and validate shear cell testers under low-stress conditions. It explores various aspects of BI, including consolidation methods and bed preparation, with sieve-filling found to be the most effective. It investigates how indentation factors: position, indenter size, and penetration depth affect the powder constraint factor and yield stress. Flow properties of various powders were evaluated using various shear cell testers (FT4, RSTXS.s, RST-01.pc), with results varying based on material and stress conditions. Comparative analyses of these testers and BI, confirmed the effectiveness of both RST-XS.s and BI, under lowstress conditions. However, results from BI and RST-XS.s provided different flow functions for the same powder at similar stress levels. To validate these methods' applicability, two hoppers were designed, tailored to each method. The BI method successfully predicted the necessary outlet size to prevent arching, contingent on consistent filling methods (sieving) in both the hopper and indentation tests. While the RST-XS.s shear cell testing recommended larger outlet sizes which were effective irrespective of the filling method.