I did it primarily via a process of elimination:
- eliminate all-female and/or all-mature colleges (obviously

)
- eliminate colleges that I considered too far from the centre (i.e. Girton, Homerton, Fitz, Churchill), or too far from the faculty (lectures)
- eliminate colleges that I considered too small or too large, both in terms of grounds and number of (undergraduate) students
- eliminate colleges that I considered consistently performed badly (below 10th) in the Tompkins table
- eliminate colleges that did not have an internal DoS for Economics
- eliminate colleges that had a poor performance for Economics in the year before I was applying (by looking at the class lists for that year outside Senate House)
This left me with Emma and Pembroke, so I booked open days for both, but Pembroke's was first (in the Easter holidays) and it was just amazing so I was pretty much decided by the time I went to the Emma open day (which was in the morning of the University open day and didn't match it).