Reverse Shaping

[Neutronmom]

Hi, I consider myself to be at the intermediate level but this is way over my head.  I’m making a long cardigan from a pattern which has instructions for the back and left front ONLY.  Essentially, you’re on your own to figure out the st pattern to shape the right : “RIGHT FRONT Make same as Left Front, reversing all shaping.”
Sooo after many searches, I’ve come up empty for a ‘how to’.  Lion Brand’s website has a blurb about it but it’s a little tricky for me to grasp as I am not that experienced.  I’d appreciate any suggestions.  Thank you!

[Granny Square]

I'm not surprised there isn't a how-to, reverse shaping for 100 different patterns would entail 100 (slightly different) how-to's, because there are all sorts of shaping possibilities depending on neckline and sleeve style.  Deep breath, hold, exhale... it's trust me, it's not as intimidating as you think.

Fronts of sweaters are (commonly) just rectangles from hem to armpits. with straight-line armholes for a drop sleeve (same type of sleeve as a T-shirt) or indented armholes for a set-in sleeve, and neckline variations from round to V to scoop, square, boat...

I assume you meant to say the pattern only included one of either the left or right fronts, plus the back.

So if you make 1 front of a set-in sleeve cardigan, it probably 'indented' at the sleeve and at the neckline in different rows.  If made bottom up, the left front (that you had the pattern for) probably said (something like), if the armhole started on row 30 at the beginning of the row and was in DC:  slip stitch over 3 stitches, chain 3, DC to end.

To do the same thing for the right front, you would 'mirror' this by starting the row with a straight edge, and  stopping short at the end of the row, leaving 3 stitches unworked.  That is all mirror shaping is, you do whatever you need to do to get the shaping the same, but do it on the other end of the row.  So it is not exactly the same transaction, but it is mostly decreasing on 1 side but not the other to shape the sleeves for a while, and then the neckline and sleeves on different sides.  (bottom up construction, in reverse for top down)

The reason you don't want to make 2 fronts the same way and 'flip' one, which would cover your body the same way, is that the stitches won't match across - half of a row would have the back of the stitch facing front, the other half of the row would have their backsides facing.  It would be the same as sewing a dress and not matching stripes at the side seams.