i created a curve network by starting with fillets to do the boundaries of my part (and any areas of curvature that weren't boundries) because there are no sharp edges on it. i then used standard curves to fill in any areas between the boundries that needed it. so i have fillets around the edges, and standard curves in the center. one problem i am having that i wanted to mention, is that if i ad planer constraints to my center patches, it warps my radii at the fillets. i even added the constaints before i fitted the patches, and it still caused problems.