When you have spent hours working on knitting a sweater, you want to make sure it looks as good after a dozen washes as it did the day you knitted it because after all that work you intend to own your knitting for a long time.
Here's how you care for the things you have been knitting. Always use luke warm water. Laundry detergent is not recommended by many knitting experts. Use your shampoo. Many knitters believe that if it's mild enough but effective enough for their hair it must be good enough for their knitting. Add about a teaspoon to the water and wiggle the sweater around in the soapy water for a while then let it soak for at least fifteen minutes.

Drain the water, squashing the sweater into the bowl to get rid of the water. Rinse with luke-warm water as many times as it takes until the water is clear. Press the knitting against the sides of the bowl. Don't wring it tight as you don't want to lose the shape. Then lay the knitting on a flat clean towel. Roll the towel up with the knitting inside and press a little. You will find this gets rid of a lot of the water. If you have a mesh sweater dryer then lay it out carefully shaping the sweater to its original proportions. If you don't have one the you can just place the knitting on a fresh towel. This takes longer to dry and most people suggest changing to a dry towel and flipping the sweater over so it dries quicker.
I hope you could follow my guide to caring for your knitted items which I always consider to be part of the knitting essentials. I have a lot more information about knitting on my Knitting Essentials blog so please join me there to learn more.