When a costume designer mentioned to us her love of the Wash & Stain Bar ($6) by the Laundress, we figured it was basically a bourgeois pre-treater. We'd seen them at J.Crew, but never paid them much mind. But she swore the long-lasting bar (a mix of vegetable soap, borax and other non-toxic ingredients) rids shirts of ring-around-the-collar and cuff stains in one wash. We tried it on an old beloved banker's collar.
Lathering the areas you want to clean seems to be the key. The two-year-old soiled collar and cuffs came out remarkably clean. Like infomercial "before and after" clean. Sure, it's a little more work than we're used to, but you don't need to do it everytime you wash. Plus, it's a lot easier than taking your chances with dry cleaning or worse—taking a favorite shirt out of commission because of a dingy collar.