The arches and lockups can be improved by opening them up and populating the area in front with tables, people and stalls/ equipment. Key to this is the cutting away of the existing frontages, which is messy but achievable. Admittedly, this is a chore but once it is done the opportunities for adding detail and interest are boundless – for me, this is the fun part of modelling.
Travel by train into any major city in the UK and you will most likely see brick railway arches that are occupied by a variety of small businesses, both industrial/commercial and retail. Hornby produces a “ready to place” set of low-relief railway arch lockups