I am really glad I bought a nice blocking board kit a few years ago when I first started knitting. It was kind of expensive but worth it. My Tweedy Aran Cardigan pieces definitely needed to be blocked, especially the back piece:
The pattern comes with detailed schematics, so pinning everything to the correct dimensions was easy. I sprayed the wool with water and now the whole room smells like a wet dog.
I'm knitting the second sleeve now. I hope to have this project done in time for winter. Jimmy and I are going back east for Christmas, and then we're going to the Grand Canyon for New Year's, so I will actually be somewhere cold!