I'm not sure I understand your question. Do you have a pattern you're working from? Can you quote it? So we can see what you are trying to cast on?
However there are several methods for casting on that "move" in different directions when you're at different points in your knitting. For instance, you can use the backward loop cast on (aka single loop)in situations where the knit, or cable cast on don't work. Every knitter should know these 3 types, I think. you can view the videos here: http://www.knittinghelp.com/videos/cast-on
Without more clarification I'm not sure I can help.