This was a blanket for Project Linus, so I used inexpensive, washable acrylic yarn, with not many color options. Of course, you could use nice washable wool, too!

The project uses mitered squares if 4 solid colors and 12 variegated colors to create units of 4 squares that connect to look a bit like a quilt. It is edged with garter stitch borders in the 4 solid colors used.

The link gives general guidelines for making a similar afghan. You can easily change it up with smaller squares, different color arrangements, etc.