russian join: joining yarn can be one of the most difficult and frustrating things for knitters. i don't like having a bunch of ends to weave in, so if i've reached the end of one ball, and have to join another ball of the same color, i use the russian join. it's neat and simple, and i've never had a problem with it coming undone, or being obvious after some light blocking. i like to use two blunted needles at the same time, so i make sure that i have it all woven correctly. then it's fun to pull both needles apart at the same time. here's a good picture tutorial from knitpicks.
twisted rib: i really love this type of ribbing, how the knits pop out just by knitting them through the back of the loop. it's so simple, yet the textural aesthetic really appeals to me. this hat i designed uses this stitch exclusively.
elizabeth zimmerman's fake seam: this technique is really handy to give a piece without shaping (like a sweater body knit in the round), an illusion of separate pieces and fitting. it's just what it sounds like. i've also used this technique a lot when my pieces have suffered from really bad laddering, and it clears things right up. all you have to do is drop a stitch to right before the cast on, and then crochet it back up, picking up one thread, then two threads, and repeating back to the top. purlbee has a great tutorial here.
toe-up, two-at-a-time socks, magic-loop, with a slip-stitch heel: that's a lot of hyphenation! this is my favorite method of making socks because 1) i can try them on as i go (or have the recipient try them on while they're still on the needles), and easily customize them, 2) both socks are done at once! no second sock syndrome! i think they go faster than single socks, but others will argue it takes the same amount of time. 3) the heel is really strong and won't wear out with regular use, and 4) you can use ever last bit of your skein of yarn, knitting them as far up your legs as you want to, and 5) you only need one needle, no need for annoying double points and the possibility of losing one. i've used this method for eight pairs of socks! and there are hundreds of tutorials out there. knitpicks has a good free pattern, and melissa morgan-oakes has a whole book of how to make socks this way.
jeny's surprisingly stretchy bind off: for a sock bind-off, i use this tutorial from knitty.com. it is indeed surprisingly stretchy, making it perfect for sock cuffs! i always have to look it up again for the visual of how to yarn-over in the wrong direction.
fair-isle: one of my favorite, favorite, favorite things to knit! i'd love to do an entire sweater fair-isle! i've done about half a dozen fair-isle/colorwork projects (tradtional fair-isle only uses 2 colors in a row). remember the moulin rouge mitts? mittens and other small projects are great for fair-isle (though i've yet to try socks), because they don't take up a whole lot of yarn, and it looks fantastic! just remember to keep loose, or go up a needle size so that it doesn't get too tight (like my flora hat, which doesn't even fit on my head now (i think my problem there was that i was too worried about running out of yarn)).
**i have not received money, sponsorship, yarn, or candy from any of these people/companies for featuring their products/techniques. this is my tribute to my favorite things, and is entirely my own opinion, communicated under no duress at my own volition.