I am currently in the process of putting away my winter clothes. Before I store my sweaters, I make sure they are clean and ready to go for when I open them next winter. This also helps prevent any potential moth infestation.
First, I use an electric defuzzer to remove pills. I then put like colors together in a laundry bag and wash on delicate (with cold water, low spin), using a detergent formulated specifically for sweaters. I remove and roll the sweaters in a towel to remove excess water, and then lay flat to dry. One of my favorite tips is to check the sweater measurements as it is drying. I find that it usually shrinks a bit and it is easy to stretch back into place when wet.