I like facing my pieces.... First, I block, square up the piece.... then sew a very narrow seam all the way around using a 1 3/4 to 2 inch "border" onto the already quilted piece ( yes... it looks funny.) I stay stitch the raw edge of the seam to the raw edge of the quilt to add stability. I also turn under about a quarter inch of the outer border, press and stitch. (yep... it still looks funny)
You can see both a front and back view here where I have folded the opposite ends near each other.... ( I laid a piece of light fabric atop 'the top' so you could better see the front back differences. The back side is to the left... front view on right.
After that.... You work 2 opposite sides before finishing the remaining opposite 2 sides. I dampen/steam the edges as I iron and roll the facing to the back. I pin the entire side and allow it to fully dry before I come back and stitch the facing the same way one would finish a binding. Finally work the remaining 2 opposite sides.... This time there will be double facing fabric at the corners of the piece. Don't be afraid to remove excess.
Finally.... using the same method as previous, dampen, roll the remaining facing to the back ( angleing at the corners... press/ pin/ dry and stitch).