Wired magazine has shared the “science of decorating the perfect Christmas tree”, including the ideal bauble ratio: about 6.2 baubles to each foot (30.4cm) of tree. Smaller trees will need fewer. About 100 fairy lights to one foot of tree is said to be “a very standard rule in the Christmas tree industry”. When I was a kid we had candles on the tree, because my dad was a bit German and a...