Student life
Choosing a university city, not only a university

You will spend more hours in the city than in lectures. It deserves a place on the shortlist.
Students comparing universities abroad tend to focus on courses and rankings. The city matters as much for day-to-day life, and it is worth a column in the spreadsheet.
Language outside the lecture hall
A course taught in English does not mean daily life is in English. In Montreal, for example, there are English-language universities such as McGill and Concordia and French-language ones such as the Université de Montréal, and the city's everyday language is mostly French. Universities DB has a Montreal page that lists the universities there.
Size
Big cities offer more part-time work and more to do, but they cost more and students are spread out. In a smaller university town, the university is often the centre of social life. Compare London with a smaller UK university town and the difference in rent alone can be large.
Housing
Check whether first-year students are guaranteed university housing and what happens after that. In some cities students spend weeks looking for a room every year.
Transport
Find out how students get around. In many German cities the semester fee includes a public transport ticket, while in others students rely on bikes.
How to compare
Pick three cities and look at the same things for each: typical rent for a room, the cost of a monthly transport pass, how far housing is from campus, and the language used in shops and offices. The Universities DB comparison tool helps with the universities themselves.