Well, it wasn't soon.
We recently started Pilates. My yoga pants, made to my 3rd Blueprint, just weren't right. I made some leggings using cheap fabric and a bought pattern (Patterns 4 Pirates). They were OK, but not right. I decided I could/should try mashing up my SFD blueprint and the P4P pattern. I decided I should fix the blueprint before I did anything.
I did it!
It took a few more iterations to work out what was wrong (technically, I mean. I could see what was wrong, but I couldn't work out what it was from a construction point of view). I made a 5th pair which were rubbish, and then I made a pair which were... really good. I'm sure they need some tweaks, but they are damned well good enough.
I then, immediately, set about trying to adapt the pattern for leggings. I wasted a day trying to cheat, and in the end I gave in and followed Glenda's process. Tonight, exhausted after lots of fiddling about, I have a template for leggings with side seams. I also have a pair of leggings which are basted together... I need to take out the basting and then sew them properly but I'm to cream crackered to do it.
The next step is to convert them in to single seam patterns, which shouldn't take long. I suspect they are going to look very similar to one of my first "cheat" attempts, but we'll see.
I've also cardboarded my successful templates, cleared the kitchen sewing area, put away the offcuts.
And I've ordered loads of cheap stretchy fabrics to try some more.
I've done nothing about Christmas, so I need to stop clothes sewing and do some Christmas stuff.