Blending different design styles in a single space can feel both exciting and intimidating. Done well, it creates interiors that feel layered, personal and timeless. Done poorly, it can look chaotic or disconnected. To help decode the process, we asked five design professionals, Susan Garland, Holly Marsland, April Luedtke, Mandy Straight and Leila Hill, to share their best advice on mixing styles with confidence and cohesion.