From the Leavers lace, soutache, and embroidery to unadorned tulle, these underthings are so perfect they've inspired a trilogy of books. Look for the sets of sheer underwear embroidered with the days of the week in Italian -- a grown-up alternative to Bloomie's classic bloomers. At this writing, the Madison Avenue boutique was due to move up a block to Madison Avenue between East 67th and East 68th streets. Subway: 6 to 68th St./Hunter College. Other location: 93 Greene St., between Prince and Spring Sts., SoHo, PHONE: 212/219-0999; Subway: R, W to Prince St.