Yeah, this saying always confused me too. I'm not a very good baker in that I need a recipe and can't just reel off the proportions for a crumble or whatever. B

Yeah, this saying always confused me too. I'm not a very good baker in that I need a recipe and can't just reel off the proportions for a crumble or whatever. But nothing about "normal" baking has ever really seemed especially sensitive. Whole milk/semi skimmed, medium eggs or large, DIYed self raising flour, brown sugar mixed with caster because there's no light muscovado, milk and a bit of extra butter instead of buttermilk. Cheaper chocolate with less cocoa and cut the sugar back a bit. Usually I bake with under half the sugar in the recipe anyway. Ovens vary wildly too. Mostly all turns out just fine.