I'm definitely a beginner, so I'm not sending advice, just my (limited) experience... I've used a decorative stitch along the seam because I didn't think I could stay in the ditch well enough... I just stitched the outside of the blocks and then used a cross-hatch for inside the blocks on one and sewed a button inside on another quilt with a smaller block.. Both came out looking cute, according to my sweet quilting friends (both of whom are also beginners)
I read with great interest the comment about so many holes in the fabric with decorative stitches... That could definitely become a problem!!
I'm watching this thread for all the advice the more experienced quilters have...