A tutorial for the placement of the garterlac squares is available here.

A very cool stretchy cast-on that’s perfect for this pattern can be found here. Oops, link no longer active. Sorry. :-( Maybe try this instead, or see below.

A way to do this cloth with NO cast-on edge is described here.

Here’s yet another way to do this that starts with a cast-on of just one stitch -- perfect!!

And here’s further explanation for the one-stitch cast on -- with photos!!