In a previous life I used to be an extra in a variety of tv programmes including Crossroads, Peak Practice, Doctors and Boon! There are a fair few more that I did across the UK at this time (early 2000's) but I don't want to bore you all with those. The best thing about those days out in Nottinghamshire or the Peak District (pretending to be an elbow or doctor's foot going by) was the fact you had to get there exceptionally early in the morning and breakfast was laid on courtesy of the catering wagon. The breakfasts were fab and I have fond memories of wolfing down a full English breakfast (totally free of charge) on a freezing cold double decker bus mostly full of variety artistes making an living through any way that they could and swopping job and agency details. IE: Did you know that so and so was casting for a film in January blah blah?
Crossroads was probably the best as it was mostly filmed at the warm and cosy Central TV studios in Nottingham and the Central cafe would serve you and it was very reasonable in price and certainly less cold to sit around until you were called for your brief second of fame. See Crossroads link for my own personal account of those days back in 2001 and 2002.
It was a very random and unpredictable life-style but exciting/fun, all the same.