Wool as a fibre keeps itself clean naturally, expelling odours through moisture control, and is naturally stain and wrinkle resistant. You should not wash wool too often. Most of the time, it is enough to hang it outside to air, especially in cold damp weather. Natural wool contains lanolin. When the lanolin comes in contact with moisture, a process takes place in which lanolin is converted to soap, cleansing the wool.
It's a myth that all wool needs to be dry-cleaned. Traditional dry cleaning is a highly chemical intensive process that can have negative impact on the environment, textile fibres and your skin. If you do need to wash your wool product, keep the following in mind to ensure that it lasts and can be passed along to the next generation:

Hand wash: place your wool product in a bowl of cold water with one drop of wool detergent. You should gently wash woolens by hand without agitating them too much in the water. An excessive amount of agitation can cause the wool to felt. After rinsing two or three times, lay the product in a towel, fold it, and leave it to dry before airing it again. It can also be hung once it isn't too wet (otherwise it will loose its shape).

Machine wash: select a gentle program; use a wool or hand-wash cycle. Wash wool at a low 30 degrees temperature to prevent shrinking. Wash wool products with a wool detergent. A standard washing detergent contains enzymes that can damage wool fibers. Spin after washing in a pillowcase or in a net bag. Lay the woolen garment flat and shape it to its correct shape. Wool should not be hung to dry nor dried in direct sunlight because it may cause discoloration. 
When wool gets wet, dry it at room temperature away from direct sunlight or heat.
While many wool garments do not require ironing, smooth fabrics might look better after pressing. When pressing wool, you should always use steam. If you are ironing dry fabric, use the wool setting and avoid ironing when the fabric is totally dry. Lighter wool fabrics may take a little longer to shed their creases. Remove wrinkles by ironing with a damp cloth or steam iron on a warm iron/dot 2 setting.
For woven products only: If a garment appears stained after wear, use a soft garment brush to remove surface soil. A wool fabric can look dull if it is dusty and dirty.
To remove cigarette or food odours, lay wool product flat on a bed or towel for an hour. Woven products can be hung in fresh air on a suitable hanger.
You can refresh wool products after unpacking or wearing them by hanging them in a steamy bathroom. Steam will remove wrinkles. 
Wool products should be rested for 24 hours before wearing them again. This gives the natural resilience and spring in the wool fibre time to recover and return to its original shape. 
Hang wovens, fold knits:
Woven wool garments should be hung on shaped or padded coat hangers. Thin, hard hangers can cause stretching or misshaping. Knitted garments should be gently folded and stored in drawers.
Long-term storage:
Unfortunately, moths love wool and can cause holes if you don’t properly store your wool products when not in use. Since food stains and body oils attract moths, you should ensure your wool product is clean before packing it away in airtight bags or containers. They can be kept also in cotton bags or use cedar wood balls to help keep moths away. Alternative is to use a moth repellent but do not place directly on the garment. If you do find moths in your item, put it in the freezer for 24 hours, take it out and bring to room temperature, and then repeat again.
Extending the lifecycle:
Don't throw away your old woolen products, but try swapping them with a friend or donating them to a charity shop. In the event that you find a hole in one of your Wilow products, no worries. Our care and repair can assist you. If your wool product is beyond repair, send it off to be recycled into new wool products.