Place the batting on your surface. Lay the front fabric right side up on top of the batting.
Place the backing right sides together(down) on to the top fabric.
Stitch round the edge LEAVE A TURNING GAP!!!!
If you want to you can clip back the batting to the seam allowance, but Iusually don't as I like that extra bit of bulk on the edge for the top stitching but you do at least need to clip off the corners or clip any curves before turning right sides out through the gap.
Press the edges and topstitch round ensuring you close up the gap as you sew.
Hope that helps.
Best Becks