Take a walk down Lygon st or Hardware Lane of an evening. All the maitre d's will vi for your business with the best deal. You play it cool and you can get 30%+ off the menu costs especially in a large group (Lygon St for groups, Hardware Lane can be touch and go on tables as it is smaller).

I am a bit more shifty as I normally have the target place chosen before I even leave home and will try to make sure the maitre d' seeing me chatting to next door so I can play him off against them.

It is all good natured and they expect it.