I am also a big fan of wavy lines using your walking foot. I have done several this way. You could do one wavy line down the middle of each jelly roll strip. Straight lines always look great too and if you do them I would do one on each seam line and one down the middle of each strip so your lines will be 1" apart. Or you can combine them and do straight line SID on each seam and one wavy line down the center of the strip. Lots of options!!