Double checking Everything

I am down to the last two classes for my BSN (that's Bachelor's of Science, Nursing for all you non-nursing folks out there). Had an A going on in my last class and screwed up. I did my final presentation, put lots of research and hours into it, then I did the unthinkable. I sent my rough draft instead of the final. No one to blame but myself. Got no credit for it. I can send it in for feedback but it won't bring my grade up a letter so I get a B. Not that a B is bad, it's not, but I had an A.
So, what is the lesson from this?
1) Double check what you send in. Pull it up and look it over. Don't be in such a hurry to be done that you don't look twice.
2) Do all your work throughout the whole class. Never rely on the final to bring up your grade. What if you get sick or the computer goes down? These things really do happen. I was pulling an A and came down to a B. If I was holding a B or C, well, enough said.
3) Mark your rough drafts as rough drafts when you save them. Make them look different than the final so you don't do what I did.

Now, go forth and do your homework! Show everyone how it's done!