The quick post is - I don't. I don't swatch or block. OK, technically I block - in the washing machine.
Here's the thinking:
I used to swatch, when I first started knitting. I'd dutifully knit my little 6-inch square of yarn, measure, rip out, knit it again, re-measure, rip it out and knit the sweater (or whatever) anyway. I knit to gauge. I always have. My grandmother taught me to knit - she never said anything about knitting swatches (or blocking, either, for that matter, but that's for a later discussion), she just knit. She had a stash of pattern books that would make ANY knitter absolutely DROOL with envy! I have most of them. Some are far too delicate to even look at, let alone use to knit something. But a lot of the styles are back in fashion - it's kinda cool! She also never taught me how to read a pattern (that I remember), I just kinda had to figure that out myself. So, knitting a gauge swatch was new to me. When I came back to knitting after about a 5-year stoppage, the patterns I was seeing all had this "gauge" thing on them (this was in the 70's) - I didn't know what it was, and when I figured it out, I thought it was a waste of good knitting time to knit a small square of fabric that you were going to rip out. I never even considered knitting it, and keeping it someplace. Besides, when I started knitting again, I jumped in with both feet - my first project was an Aran pullover with a front pocket and a hood - like the hoodies my daughter wears now. Knitting a swatch gauge for that would have been a freaking nightmare! One gauge for each cable pattern? I don't think so!!!!
So, anyway - I don't knit gauge swatches.
As for blocking - pah!
It's a piece of string that you've formed into a different shape! Of COURSE it's going to look a little funky when you first finish it! But, a quick round in the washer and dryer, and, voila! You have a wonderful garment that looks like what it's supposed to look like - a sweater, a blanket, a pair of gloves or socks, whatever.
Now, I've gotta say here that I work almost exclusively with acrylic or acrylic blend yarns. I knit things that I want people to use - I want them to feel free to use the blanket I've knitted them, spill coffee on it, and know that they can throw it into the washer and dryer, and it's going to come out looking substantially like it did when it went in - maybe cleaner, but mostly the same. This is especially important in the case of baby blankets. See, I've had a baby - and I certainly did NOT have time to hand-wash some precious thing that somebody gave me. And, face it, people, baby stuff is just nasty - from formula to baby food, to juice - it all gets spilled, and it all makes a horrible (possibly staining) mess. Another point in acrylic's favor - it's really hard to stain.
I took a class in modular knitting one time. She was a lovely lady who's name escapes me at the moment, and everyone else in the class was simply awed that she had agreed to teach this class. I'd happened to be in the yarn shop she was scheduled to teach the class in one day, saw the sign-up and signed up. Anyway, she said that her favorite blocking technique was the washer. So, I felt vindicated.
There's nothing like a quick spin in the washer (full wash/rinse cycle) to make a sweater behave like a sweater. And, if it's acrylic - toss in the dryer, and you can wear your new creation the same day you finish it.
That's another thing about me - I have no patience.