as the weather is warming up its time to think about changing from the warm flannelet sheets to your soft cool cotton sheets, swapping heavy doonas & blankets to light weight feather or summer doonas.
as these items are quite expensive you want to keep them in tip top shape so they last for years
either air out or wash depending on the type of blanket
if washing you can add 1/4 cup of bath salts to the final rinse it will make them smell nice for months.
if just airing out before you store them, think about storing in plastic bags/vacuum bags or plastic storage boxes & placing a bar of soap in between the folds, when you come to using them again they will smell fresh.
for woolen blankets like knitted / crochet use a wool wash & store with a bar of soap. wool wash is also good with your flannelet sheets before you store them for the summer.
when storing in plastic make sure they are dry all the way through even a little damp will cause mildew.
blocks of Camphor in your linen cupboard & wardrobes will keep away moths & smells better than moth balls.
EDIT: you can buy Camphor blocks in the supermarket & chemists