Press two separate pieces of fabric.
Align the fabric pieces and pin to secure
1″ seam 
5/8″ seam 
1/2″ seam 
1/4″ seam
Load the pinned fabric pieces on the sewing machine.
Align the edge of the fabric pieces according to the width of the seam.
Press the sewn seam flat on both sides
Press open the inside of the seam
Press the surface
Examine the seam.