A Brit who when demonstrating some sort of art or craft says "Here's one I prepared earlier" is often referencing the Blue Peter art segments where they would s

A Brit who when demonstrating some sort of art or craft says "Here's one I prepared earlier" is often referencing the Blue Peter art segments where they would start to assemble (say) a model of Tracy Island from 'sticky back plastic' and toilet rolls and then cut to a superbly finished creation. It's the artistic equivalent of Step 1: take these household materials, Step 2: ???, Step 3: Profit!