Banner design tips : Attractive web banner can enhance online business for a company. Catchy slogans, sharp and aesthetic images, vibrant colors, call to action buttons and precise information can make a successful web banner. Size of the banner is also important. Banner ads can be missed if too small or difficult to read. Large banner ads can be annoying and irritating. Medium sized banners are best as convey messages without infringing on the sensibilities of the visitors.