1. Cut jeans/pants into squares. I prefer 7" X 7" because they end up about 6" X 6", which makes for really easy measuring. I use some of the pockets, but they are harder to sew because of the thick seams. I cut squares so a seam falls in the middle. I like how it looks. You get about 16 squares from an adult's pair of pants.
2. Design your quilt.
How big will it be? Twin: 12 X 14-15 squares, Crib: 8 X 10 squares, Queen: 15 X 16-17 squares, King: 18 X 16-17 squares (I looked up standard blanket sizes and divided by 6 inches to get the number of squares I needed.)
Colors? Vary the colors of jeans. If you have tan and black (or other colors), you can draw out a design on a piece of paper first. Or, use Excel! Here's an example for a twin quilt:
3. Arrange squares into rows and tie/rubber band them together. The more complicated your design is, the more important this is.
8. Tie the quilt. I do every other square. Grosgrain ribbon won't fray.
9. Fold the back of the quilt (sheet) over the front twice, pin, and sew around all edges.