A tailored suit is a traditional option for interviews in conservative or corporate work environments. Tops or blouses don't typically come with suit separates, so you'll want options that are appropriate and convey a professional appearance. Stick with versatile basics to show the job interviewer that you mean business.
A crisp, clean button-down shirt is an investment item and a basic foundation for your suit. Stick with solid neutral colors that easily transition through the seasons -- think black, white, gray or navy. A thin pinstripe is appropriate when paired with solid suits, but avoid an all-over print or design. Tuck your button-down into the waistband of your bottoms to maintain a polished and professional appearance.
A silk or jersey silk blouse adds feminine appeal to a tailored suit. Other opaque materials work as well, just avoid anything too revealing like sheer fabrics or lace. A neutral color is versatile, while interesting details like a high neckline, tie-neck or a Peter Pan collar add visual interest without being too trendy. Prints and embellishments are appropriate in creative work environments as long as they're small and don't overwhelm the ensemble. Stick with sleeveless or cap sleeved blouse styles as they easily layer and keep you cool underneath your blazer.
A solid neutral colored sweater layered under your suit adds dimension and texture to an otherwise basic ensemble. Luxurious fabrics like silk or cashmere make a sweater suitable for an interview and less weekend-ready. Cap sleeves or three-quarter length sleeves are a versatile option that won't add volume underneath your suit jacket. Stick with appropriate necklines that won't interfere with your suit jacket -- think a boat-neck or slight scoop-neck. Avoid plunging necklines that show any hint of decolletage.
A camisole is appropriate for an interview as long as it's in a dense fabric like polyester, silk or rayon. Avoid lace or anything sheer, which will give your camisole the look of lingerie. Your camisole shouldn't be overtly tight or have a low neckline -- a camisole that has adjustable straps is a good investment as you can raise the neckline if need be. Steer clear of feminine details like bows or ruffles and instead opt for solid neutral colors that keep the look professional.