Peel the asparagus with a peeler and cut off the woody ends (about 2 centimetres).
Place the peelings and cut ends in water and add salt. Use them to make broth. (Some cooks prepare a broth with the peelings first and then boil the asparagus in it. You may decide you want to prepare it this way as well. If you boil the peels with the asparagus, the asparagus will be slightly less white than usual).
Place the peeled asparagus in a suitable bowl and pour water over it. Be sure to use a measuring cup so that you know exactly how much water you're adding. Make sure that the asparagus are almost completely under water. Add the salt and sugar.
Cover the asparagus with a damp cloth and bring to the boil.
If you've prepared the asparagus in advance: let it simmer for 2 minutes, and then take the pan off the heat.
Leave to cool in the water. Serve the asparagus as desired.