I have made a few of these quilts. Stitch in the ditch first. Then quilt around each design but not on top of design. It really depends on the type of screen print they used. Some of the shirts have a heavy/rubber feel and others are nice and soft. The soft ones you can quilt on top of and leave no needle holes. The heavy one will leave holes. I quilt around each letter and the main design some times, where there is no pattern I do small patterns that match the shirt design. On the boarders I usually do a wavy or straight design. On your's I would use foot prints.