I decided to use a Cross-Hatching design on my DP9. I used a walker foot for this project because the walker foot is great for quilting long straight lines and geometrical angles. I have also used the walker foot for Echo quilting and making wavy lines. The walker foot is a machine guided attachment with the feed dogs always up to my knowledge. If your design requires more free motion quilting then you will most likely want to use a darning foot aka FMQ foot and your feed dogs would be disengaged (down position). Diamond Grid, Echo Quilting, Stippling, Meandering are just a few other quilting designs that can be used.
A great source of information on the Walker foot and Darning foot and also on Quilt Designs can be found in the book pictured. I highly recommend this book to everyone. Especially beginners and intermediates.
The Quilters Ultimate Visual Guide, From A to Z--- Hundreds of tips and Techniques for Successful Quiltmaking. Ellen Pahl, Editor
Here are a few pictures I will share of the back side of my quilted blocks.