Bright, indirect light. Long spaces between leaves are caused by too little light. Pinch off leggy stems and move your plant to a brighter spot. Leaves will also lose their variegation if they don't get enough light.
Keep soil evenly moist in the growing season, slightly drier in winter. Stems that look wilted may be a sign of root rot. Cut off any withered stems and allow potting mix to dry out a bit between waterings.
Feed every 2 weeks spring through fall with 10-10-10 liquid fertilizer diluted by half. Too much fertilizer can cause the leaves to lose their variegation.