You just want the flow of your holding edges to go in the right direction not to interfere with the outside curvature:
Often, you can avoid hand-work by Beveling with segments 2, profile 1, or to leave adjustments in play, you could use a Bevel modifier .. If so, you could look into controlling bevel-widths by edge Bevel Weight.
Even if you're not going to keep the Bevel modifier alive, (you're going to apply it,) the modifier can still make selection more practical. It's often important to bevel crossing edges simultaneously. The result of beveling one edge, and then a crossing edge, is different. So accumulating the right selection to go off in one shot can be a pain. Assigning Bevel weights, applying the modifier, and then setting all the weights back to 0 can make that easier.