Watch Neil talk you through some principles of materials design for TBLT. There is a folder of sample material to which some reference will be made, so it might be an idea to have this open. The presentation is available for download from the materials tab.
Please note that the Long (2019) article referred to is the one shared in the reading activity (listed as Long (n.d.) and in fact now Long (2020)). Aside from this and the other main reading resources for this session, reference is made to the following: