The right time to dig them out is when the foliage of the bulbs start to yellow because of the first wave of the cold. You have to dig them out before the cold arrives. Using a fork and spade, loosen the soil around the bulb and dig it out intact without any cuts or blows to the main section and the stored food. Do this for all the bulbs.
Shake the soil out of the bulb or rinse them with gently with running water. Cut off the excess foliage from the bulbs without damaging the main section. Let them dry outside for a day or two. However make sure they do not freeze in the cold. Discard any diseased ones as they will not be able to endure the winters. Apply pesticide or fungicide powder to the dry bulbs.
Get different containers like paper bag, open crate, or pantyhose for each type of bulbs. Always go for a material that can breathe. Plastic bags cannot do so, avoid them as your bulbs will rot. Fill the containers with a loose storage medium such as peat moss, vermiculite, newspapers, or sawdust . Place the bulbs in the containers in a way that none of them is touching each other. Cover with the filling material and close. Store in a cool dark place like the basement.