first of all, I'm new here and not much of a knitting expert yet, but I have a tip I haven't seen on the web yet, so I want to share it.
I'm currently knitting my first double-knitted socks and was faced with the problem of having to decrease stitches for the toe. So the "normal" way is to slip stitches around to get them into the right order and then knitting them together. However, since my sock increases are regular (knit the first two on each needle together every second row), I've found a better way:
In the stockinette round, I make a mini cable of sorts. That is I'll knit the first stitch in color A, then knit the second stitch in color A (which is now the second stitch on the needle), purl the first stitch in color B (the first one on the needle), only then slip these two stitches off the needle. Then I just continue with a purl stitch in color B, k A, p B, and so on. In the next round you already have the right stitches lined up and you can decrease as you would with normal socks.