A while back (March 18, 2014, to be exact), I wrote a post about a technique I created to avoid the dreaded sock gap that invariably appears when turning a heel. That was a so-so solution. Now I have a better one, at least for toe-up socks, if I can explain it in a way that makes sense.
What causes the sock gap is the final purl-back-knit-forward of the short-row heel turn. This creates an extra row, which creates a gap, which leaves a hole if one doesn't pick up some stitches from below. This solution is to not create that extra row. I accomplish this by not purling back to pick up the final wrap but knitting forward and picking up the wrap on the next go round.
Picking up that final wrap going forward can be fiddly and you may decide it's not worth it, but it satisfies my need for a logical and balanced solution. Left brained and a Libra am I. Also, some say wraps don't need to be picked up, but since the heel receives so much wear, I'm afraid to skip picking up wraps.
When knitting a short-row toe for a toe-up sock, the toe always seemed a bit skewed to me. Not enough to make a big difference, but just enough to bug me. It turns out the same trick may be applied here: instead of purling back to pick up the last wrap, knit forward and pick it up when you get to it. Now my short-row toes lie flat.
If you try this trick on either heels or toes, let me know whether it works for you or if I can explain it better.