Groups of settings for vector layers can be saved and loaded. These are saved in .qml files that can easily be shared between different users.
You can download a starting set of styles from here. After downloading the zip file, unzip it to a convenient location and then you can load the style using a layer’s properties tab.
These files can also be used with OS Tools to define the default styling for Ordnance Survey layers.
If you have further styles that you are willing to share then please contact us.