I considered the distance of each accommodation to things like bus stops, the building mostly related to my course and other buildings like the Student Union, sports areas if you're interested, etc., or for city accommodation, then the distance from bus stops and grocery shops. You should be able to find a map of the campus from a quick Google search and also be able to find out the building of your course. But I do think factors like food and drink credit, city vs campus, ensuites and price are factors that are in more need of prioritising. You can also find pictures of the rooms on the website, I believe, so I also based my choices on which rooms I liked the layout of more!