To use the FMT - you first MUST layout the location of the centers of the tenons or mortises for each type of part. For the the apron parts you MUST layout the center location on at least one apron part - unless the tenon is perfectly centered on the arpon part - in which case you only need to layout the center of ONE tenon (or mortise).
So you've got your apron part - and you know which way is UP and which face of the part is the SHOW FACE. You DO want the Show Face to actually show - right?
Here's what YOU are going to have to do - to cut the first apron's tenon.
So far - so good. One end cut - on the the OTHER END -------->