No there is no set rule. You can weave in any direction that you feel comfortable with. I usually weave right to left with my first row, so my second row is woven left to right and so on. I also normally create the top of the weave first and weave my way to the bottom, I feel like it gives me more flexibility. But I know a few people who start at the bottom of the weave and weave up.
The Weaving Loom Great to know! I do some weaving but was taught always left to right. It has been limiting. I can't wait to try out something like this! Also your post on your web site about making curves and shapes has been tremendously helpful so Thank you! 😀💕