That is a good article.
I used to knit tightly and I was constantly getting frustrated. It's the very reason why I gave up on knitting for so long. Then when I went back to it, I picked up a larger set of needles (7mm) and some chunkier yarn to knit my scarf -- I had to literally concentrate on what I was doing and purposely pull the working yarn a bit loose because I was in the habit of "tugging" it after the stitch. I still catch myself doing it sometimes, but not nearly as much as I used to.
And now...lo and behold! I've finished my frist two scarves and am now almost done with the third, with plans to move on to an afghan.