I just finished this quilt top, using Y seams for the first time (I know, the points are no where near perfect

). Now I need some advice on how to quilt it. I think I will use variegated blue thread, but I can't figure out how to quilt it. I have a sweet 16, but my skills are still not that great, so I can't do anything too complicated. Thanks for your advice! I hope the picture shows up.