What I should do: Hand wash in cold water using Woolite; lay flat to dry.

What I actually do: Wash with normal clothes (on cold). Dry with normal clothes.

FWIW I source most of my stuff from gently used items on ebay. Sweaters begin life as office attire, and when they get grubby, they become bike-only layers. The sweaters really shouldn't be dried, but I've only had one shrink at all after about 20 washings. It is still wearable. They do tend to pill more when dried.

I also had a dry cleaner seriously screw up my wool sweaters once, so I don't bother with dry cleaning.