I am in the process of putting together a Quilt-as-You-Go quilt right now. I quilted 13-1/2 inch squares with front, batting and back, and then put them together into rows with narrow sashing/binding. Now I will go back and put the rows together. The front and back look identical if you hand sew the sashing on the back to secure after finishing the front by machine. If you stitch-in-the-ditch from the front to secure the second edge of the back sashing (after completing the front and sewing the back sashing to one side simultaneously) it goes a lot faster. It looks good if you take your time. This is what I am doing. To make it easier to sew the sashing, take one half of your quilt at a time to assemble. Then with the final two or three seams you can sew the two halves together.
This method offers endless design possibilities. You can make your back sashing match the backing, or use one or more contrasting fabrics. The quilt I'm working on is reversible, because for each square I used the same fabric both front and back. I also used the same fabric for the sashing front and back.
There are other methods. Some even quilt the front and batting of each square, sew the squares together, and then put the back on and stitch in the ditch around each square to secure. The batting must support the distance between stitching, and you still end up wrangling a whole quilt through a harp space to outline quilt each square. I don't see much the advantage in doing it that way over quilting the entire quilt. But other people do. Why not try a small sample quilt using each method and see which you prefer.