Yeoutch...
Health related: I wound up in hospital with near sepsis from shoes I made but didn't put a good lining on. I chafed my toes raw and they got, well manky. next stop ER. Though a month later...
Epoxy allergy of doom. Triggered purely by my stubborn bloody mindedness to make my own gear- which either is attributed to a bloke or is then assumed to be paper mache or polymer clay!!!
On site: Nothing terribly major so far, I tend to go overboard and glue myself into everything I can. Literally glue, with PA as it grips skin and cloth and prosthetics.
Assumptions in general. Tiny fists of fury while I smile politely and make an excuse to hurry away. At cons I always have my official hat on as part of the organisational team (costume contest, etc) so I can't say too much on a personal level
Epic fails:
Oh man, my Samara head sculpt. Not she sculpt. I had a blast. But I had to sculpt the thing four or five times because my mold making was such epic fail. Partly me partly the medium. Plaster is horrible. It wasn't until I got my mitts on some ultracal that it was suddenly easy. made Shaak Ti a heck of a lot easier (one sculpt one mold. So happy)
I'm generally really good with fabric and can by amounts smaller than most people would and know I could cut what I need and not need to replace. However I am not above nicking too far when clipping curves. A few near misses- you can't glue or even sew a cut in fabric. You have to replace the whole panel. But hooray for learning techniques from practically every century (and these are extremely different).
If my rotary tool was really grunty I would have lost a few digits by now....