Measure twice, cut once!

Such a good piece of advice, although often in my haste to get on with it and get it made, it's advice I don't stick to.

Surprisingly, this framed 'Measure twice, cut once' sign appeared in the Cycle Revolution exhibition at the Design Museum, running until June 30 2016, but it's as valid for making a bike frame as it is for sewing a pair of pedal-pushers.