In addition to picking up some knitting tricks, I've become way better at doing laundry. In the past, I would never hand launder anything, and rarely buy anything that required hand laundering. While still not a fan, I now have a much better idea of what tags that say "hand wash only" mean it.
For instance, if a sweater is more than half acrylic, it probably will not shrink in the washer on cold. In fact, anything not 100% wool will probably come out fine if you stick it in a mesh zipper bag (to avoid weird sleeve stretching), on cold, and don't put it in the dryer.