Public reports are prepared to inform investors or potential investors and their advisers on exploration results, mineral resources or mineral reserves. To convert mineral resources to mineral reserves, mineral processing and geometallurgical factors are used. The International Reporting Template (IRT) is a document that represents the best of the CRIRSCO-style codes: reporting standards that are recognized and adopted world-wide for market-related reporting and financial investment. In this reporting, geometallurgy represents a key component in the checklist for reserve assessments and reporting criteria: (1) mining factors or assumptions: in order to demonstrate realistic potential for eventual economic extraction, (2) metallurgical factors or assumptions: to demonstrate realistic potential for eventual economic and optimal extraction, (3) study status of mineral reserves for all modifying factors that have been considered and (4) cut-off parameters: the cut-off parameters may be economic value per-block rather than grade, and the costs of processing a block depends on geometallurgical parameters. An overview of good practice to estimation and modelling techniques of geometallurgical data is given. A discussion is provided that of ore-type definition, types of test samples are critical, density of sampling per geometallurgical domain, relationship between mineral characterization and behavior of mineral processing to support geometallurgical modelling (some multivariable tools are proposed), how geometallurgical modelling supports the long term scheduling (costs, efficiency, recovery and mineral mixing among others); and simulations of geometallurgical scenarios to quantify uncertainty and risk of mineral processing. Currently, no guide exists for the construction of geometallurgical models and their management in the quantification of reserves, therefore, this research supports companies that declare mining reserves in bankability studies and private consultants that generate this type of reports.