Since you have to change threads regardless, you can do it either way. I float my quilt tops and baste alongside the beginning section of what I am quilting as I roll to each section. But I, also, don't roll the quilt back and forth a lot. I would do each section as I rolled through it one time. But since you may want to do a certain pattern in parts of the black, you may want to that design in each section, then roll and complete all that design. It just comes down to what you are more comfortable with. Now, hopefully, Feline Fanatic or some of the other much more experienced quilters will give you the real way to do it.