I always line baking tins. The non-stick promise that so many tins and pans throw around is a lovely sentiment, but so often disappoints. I usually end up ruining their good intentions with a spoon/knife/pick axe trying to lever my cakes and bakes out of their grasps when they invariable get very firmly stuck to the bottom anyway!

Lining a square or rectangle is fairly straight forward but getting the perfect sized disc can sometime result is a lot of wasted paper.

To line the round pan bottoms perfectly cut a section of baking paper from the roll that is the length of your pan's diameter to give yourself a roughly square sheet. Fold the paper in half to make a rectangle, then in half again to made a square a quarter of the size of the original sheet. Fold into a triangle so that the acute corner is the one that sits in the center of the original square.

Position this point at the center of the baking pan and measure the radius of the pan, cut the excess paper off then unfold to reveal a perfectly sized disc of baking paper with which to line your tin.