You do not need to wash your woollen items very often; once every season might be enough.
After wearing them, leave them outside in the open air, if possible, or just on a hanger or a chair, for a couple of hours before putting them away.
Always use moth repellent from Spring to late Summer. Store your items each in a separate bag with one moth ball or sheet per bag.
When needed, hand wash gently with delicate detergent, or use the wool wash cycle (at 30°) of your washing machine with the lowest spinning speed available. I promise they won’t be damaged! Then lay flat to dry reshaping them carefully, away from direct sunlight.
If your item needs a bit of ironing, do this at low temperature on a steam iron, but do not actually press it, just hover very close to the item with the steaming iron and the fabric will relax without looking flat.
With the right care you will be able to enjoy your woollen garments for a long time and they will keep looking and feeling like new.
This way you will also help the environment.
Buy less but buy well and take care of your items!