To test out CivitAI's built in lora training I tried to do my own Posey Straitjacket lora for Illustrious. Although it is trained on real images, this version does not work well with the realism loras. A few notes:
Add "buckle" to the negative prompt if you want to avoid the issue with a random buckle appearing at the top of the front arm loop.
It (mostly) understands neck stripes. Just add {color} neck stripe. Despite being trained on some images with white neck stripes for some reason it outputs blue when you prompt for that.
It understands the concept of a crotch strap, and if you include it in the prompt then it will almost always show up. If you don't include it in the prompt then it may or may not show up.
I tried to get it to understand the concept of struggling to have more flailing arms, but that didn't really stick.
I tried adding front view, side view, back view, and three quarter view. Side view didn't come out very well. Front and back view work well, though add "5 buckles" to back view for more accurate back buckles. They still sometimes come out a mess though.
Overall it's a complex concept that I may need to pull into something more customized to iterate and figure out. If anyone has tips they'd like to share then I'm open to them.