hello again! i'm a self-taught newbie weaver and because i don't know anyone who weaves, my questions could be pretty basic...but i'll ask 'em anyway ;) 

--when you warp on a frame loom do you need to wrap the warp over and under to create a cross? i've just been going around the frame and then going over/under back and forth. IF its a better idea to create the cross, do you start the weaving project ABOVE or BELOW THE CROSS?? dying to know.

--also how important is the back of the tapestry or weaving? should it be as perfect as the front or can it be crazy-looking? does having a crazy-looking back "undermine" the project in any way??

ok these are my most pressing questions--thanks so much for your help!