OS Open Map Camper style
Here's another set of QML files for QGIS for styling up the new open data Open Map Local from Ordnance Survey.
It's a little bit retro and uses nice clean colours and some different fonts. It doesn't use all the layers from Open Map (that's the beauty of working with vector data) and allows you to overlay your data without being too distracted by the good looking (IMO) background context.
You can get the QML files from GitHub.