Until now, the systematic testing of design choices in MM force fields has been rather limited, and it is almost impossible for individual users to undertake this task due to the scale of the parameter optimisation problem. In what follows, we describe our interface between the QUBEKit and ForceBalance software packages. This open source (including all dependencies) software workflow allows users to make a choice of force field hyperparameters, train the model against experimental liquid properties, and unambiguously test the resulting accuracy. We provide improved protocols for deriving the positions and magnitudes of off-site charges (virtual sites) to model anisotropic electron density from the output of atoms-in-molecule electron density partitioning calculations, as well as tools for including them in torsion parameter fitting. Using a train/test split of 15/51 small, organic molecules, we develop 15 force field protocols that aim to test the accuracy of different choices of i) underlying QM method and basis set, ii) atoms-in-molecule electron density partitioning method, iii) implicit solvent model parameters (used to pre-polarise charges for use in the condensed phase), iv) mapping of atomic electron densities to LJ parameters, v) assignment of Lennard-Jones parameters to polar hydrogen atoms, and vi) use of virtual sites to model anisotropic electron density. We show that a wide range of different choices can be made in the force field design process, some of which do not affect the overall accuracy, and some of which show marked improvements. For our best performing protocol, we provide all of the parameters required for users to derive their own force fields using the QUBEKit software.