What the hell is a pro-forma invoice, anyway??

I cannot tell y'all how bad I am at shipping things internationally via FedEx. Like 80% of the time I get a call from FedEx International saying I screwed up the commercial invoice. Why they can't make this easier, I have no idea. (And in case my brother who works for FedEx happens to read this...WHY CAN'T YOU MAKE THIS EASIER) And yet I never learn and continue to send things out like I always have. Which means most things get stuck in customs. I really need an assistant who can do this crap for me. And probably would do a much better job. Just saying.