I don't buy the large sized milk, but have cut up any margarine or icecream tubs to make labels for years.
Usually at this time of year I get my daughter to save her big milk bottles, as with some of the tops bit cut off they make a big enough pot for starting courgettes and squash off, without having to do any potting on when they grow soo fast before they get planted. Also good for 3 or 4 bean seeds - I pot per cane
My neighbours save enough of their small water bottles for me to start my sweetcorn off in them
