I have the grain line and crotch line marked with thread on test fabric. (97% cotton/3% Lycra).
I’m making shorts. The grain lines hang perpendicular to the floor except the right front. It begins to swing out at the crotch line and then swings towards the side seam gradually below the crotch line. When I pull the right CF up a tad, the grain line straightens but then the front crotch is too snug, particularly the right.
I’ve played with the fabric at the waist at the top of the right side seam and along the side seam below the crotch line. I haven’t come up with a solution so that the grain line hangs better.
The front and back crotch lines hang parallel to the floor.