I would suggest a varigated as well. Try your local quilt shop for YLI thread that's varigated that will contrast with your back so it will show. Would stipple it - good experience builder, just be sure to get some machingers gloves to hold your quilt with as you are quilting. As for criticism - you did a good job. Do you have a quarter inch foot. Learning to sew 1/4" even with the foot takes practice. Now I also make sure my blocks are "square" the size I want them, because I also have a tendency to not always cut them square (LOL). I use a strip cutting ruler and it makes a lot of difference for me, but still have to make sure things are square. Congratulations and you just keep on a quilting. I learn something new with every quilt I make