Funnel from plastic bottles

This is a case where necessity was the mother of invention - I needed a narrow funnel to fill a jar of bath salts that I made. (Left, out of a 2 liter bottle and right from a 1 liter bottle) Start with an ordinary plastic bottle. Holding the bottle horizontally, pinch it just above the top of the label and make a cut into the bottle. Cut all the way around the bottle just above the top of the label. Flip the top of the bottle upside down and you have a narrow mouthed funnel.