Knitting question

[sugarcoatedlie.livejournal.com]

I'm knitting myself the Cleaves shrug from Knitty.com. I've finished the sleeves and it's time to cast on for the ribbing around the shoulders, but the pattern calls for a cable cast on, and the directions aren't making sense to me. Neither are the directions in the SnB books. I'm worried about trying another CO method, since I'm already a really tight knitter and I'm worried that my cast on won't be stretchy enough for the ribbed piece. Does anyone have any suggestions? Maybe better directions or a video or something on the internet? I'm a pretty decent knitter, and have made stuffed animals and things, not just scarves, so I feel like this is probably something that I should be able to understand that will seem so obvious once I see it done, but I'm just not getting it!