The first technique was Helical stripes (which I've seen previously referred to as helix stripes) with a pattern from Jenn Arnall-Culliford, Hyacinthus Armwarmers, a pair of mitts in self-striping Zauberball fingering weight yarn.
It took me the whole month to knit these around caring for a newborn and preschooler; if I can finish a project in the allotted time with those restrictions it's a reasonable target for even the slowest or most time-strapped knitters! I did do a lot of "yarn management" - ripping out sections of yarn to arrange the colours in a more pleasing way - starting when I hit a join in the yarn and my red abruptly turned into yellow!
Helical stripes were a strong opening act, for me, as the only technique on the list that I hadn't tried before. I'd read about them in a TechKnitter blogpost on jogless stripes but never actually used them in a project. The other techniques, which include things like Judy's Magic Cast-On and turning a heel which I consider myself proficient at, and techniques that I've done but could use more practice at like grafting in garter stitch and steeks.
I'm also having fun guessing which designers will be working with which techniques. I am four for four on April's design, which comes out on Tuesday: Bristol Ivy (1) designed an Intarsia (2) shawl (3) in Fyberspates Cumulus (4). My guess for April is Rachel Coopy, after-thought heel socks, in her own Coop Socks Ya yarn (that last one is easy as it's the last yarn in the spring kit).