Beware the potential for death spirals, and the bigger you get the harder they are to see. Early on, this is easy; last long enough to get to a profit. Later, if you have several products and you're allocating overhead among them, you could be tempted to cut the one with the worst margin. Then the overhead gets reallocated to the other products and pushes a second line underwater.

If your output requires direct labor, it IS possible to sell your way into a death spiral because labor is short-run inelastic.

Know your experience curve and know where you and your competitors are on it. If the curve has flattened and you're not the winner, find a new curve.