I've watched Only Connect a couple of times, but it always seems fiendishly difficult; asking the contestants to connect seemingly unrelated pieces of information together. A perfect opportunity to test some of my students then.
The rounds change slightly as the show progresses but I attempted Only Connect's Round 1 with one of my KS4 classes. Rather than me trying to explain how the round works in a convoluted way, Wikipedia sums it up much better:
Teams are given up to four clues and must try to figure out the connection between them within 40 seconds. The team is initially shown one clue, and may request the remaining three clues at any time within the 40 seconds (they are not automatically shown). The team may press their buzzer to guess after the first clue for 5 points, the second for 3, the third for 2, or the fourth for 1. If the team guesses incorrectly, or fails to buzz within the time allotted, the question is thrown over to the other team for a bonus point, after being shown any remaining clues.
This format was then applied to the scheme of work my KS4 class were studying at the time: Of Mice and Men. This could be done with particular bits of information that I wanted them to recall from the previous lesson e.g. the symbolism of 'red' as a colour in the novella:
This information could have simply been told to the students, but they seemed to engage in the process of the 'game show' format whereby they were competing against each other trying to connect pieces of information together that on the surface shouldn't connect. One piece of advice is to use as unrelated bits of information as possible as you will get the inevitable cries of "they're all in Of Mice and Men" and the like!