If You Want an Eclectic Look
Pillow number and placement: An even number of pillows runs counter to the spirit of an eclectic room; three or five create a pleasing asymmetry without cluttering the sofa. You want your pillows to look "as if they just happened to be there," says Ridder. For a casual air, try two pillows in one corner with a third at the opposite end.
Shape and size: Pick similarly sized pillows to tie together a diverse collection. Generally, interior designers prefer a few large pillows―18 to 24 inches across―over a mishmash of smaller ones.
Fabric: Be open but not random. You can have a couple of pillows that match or five pillows in five different fabrics, but make sure there's at least one color in common to give the arrangement some unity.
Trim: Avoid excess; keep trim simple and express yourself more through fabrics. Box pillows, with their square shoulders, can be attractive in an eclectic grouping and look great when edged with braid, says Leigh Anne Nomberg, an interior designer with Bill Ingram Architect, in Birmingham, Alabama.