I will admit that I don’t always block all of my knitting projects, so I’m still impressed at how much better things look when I do.
Blocking is a really helpful step in finishing if you’re going to be sewing pieces together, but it’s great for any project you want to look its best.
Blocking smooths out your stitches, can help with minor sizing problems and just makes your project look better. 
It’s kind of a pain because when you finish something you want to wear or use it right away, but in a lot of cases it’s well worth the wait (and when it comes to lace, it’s essential, but we’ll talk more about that tomorrow).
I pretty much always do what’s known as “wet blocking,” meaning that you get the item wet (which I do by soaking in the sink or a bucket for 30 minutes or so, usually with a squirt or wool wash), get out as much water as you can by rolling the item in a towel and pressing, then lay the item out on a towel and, if necessary, pinning it into the shape you require.
Pinning can also help smooth out the edges of stockinette pieces, which will make them easier to seam.
There’s also spray blocking, where you pin the garment into shape first, then spray it with a bit of water to relax the fibers and get them to smooth down. There’s a detailed tutorial on this over at the Purl Bee. Or steam blocking, which is done the same way, except you use a steamer or the steam setting on an iron to push the steam through the garment.
The big warning on that is to make sure the iron doesn’t touch the knitting, so it doesn’t scorch. Some people use a piece of cloth over the knitting, or you can just be careful to keep the iron a couple of inches away from the garment.
Blocking is typically done on wool and other animal-fiber garments, but you can do it with other fibers as well. Check out this article from knitty that covers ways to deal with different fibers, and even how to make your own blocking board if you want to get fancier than a towel on the dining room table.
Do you ever block your knits? I’d love to hear what method you use!
[Photo via the Purl Bee.]
When I lived up north, the cold water was always cold enough to stiffen my wool items so that I could lay them out to block/dry.
Recently I tried to wash and block a wool scarf here in Texas. It grew and grew in the tepid “cold” water. I now realize that I need to add ice cubes to my final rinse to stiffen the wool fibers.
Lesson learned.