I started with the ballet style ones in pink:
They were quite easy to do, and not too fiddly.
I have one blue one made in the button style and will post a pic of that one when done. The button ones are trickier as you have to rejoin the wool at a couple of places at the end and I haven't gotten that perfected yet. I also found the part of the pattern where you have to cast on extra stitches for the ankle pieces a bit difficult to decipher, though what I ended up doing worked.