How do you cover a large carved cake or odd shaped cake in fondant? Do you do it in pieces? and if so...how do you do it so that there aren't seams? I haven't done too many carved cakes/3D cakes, but want to try!

I'm not sure what the other decoraters do, but if I'm covering a large cake, I roll the fondant out onto a big sheet of plastic, that way I can jst flip the plastic over onto the cake..

If it is a large flat surface, then yeah, the plastic sheet thing works great. If it has areas where it sticks out considerably, or needs to be tucked in in places, then sometimes you do need to do it in pieces. It really depends. Knowing the shape of this cake would be helpful, could probably offer some better advice. If you do slap a big piece on and try to tuck and smooth around areas that are tricky, you could end up tearing.