I'm sure you can find much better instructions than this, but it worked for us. I trimmed the edges as needed (one piece was the end of a bolt), laid both out flat on the floor, on top of the other with the right sides facing out. Then I started cutting the fringe, taking out the square corners as I went. Before moving to another edge, I loosely knotted the two blankets together. Once the entire blanket was knotted, I went back, tightened a bit, and added a double knot. And now we have a pretty baby blanket!
The picture will be so much nicer once an actual baby is on it!