I was taught you can sew over pins also. I try not too just because you hear so much about it. Most machines now days are made to do that. You have to make sure your pins are put in straight so it goes over and the feed dogs can push it through.
I am too picky and makes my sewing last so much longer, I am trying to mellow a little on that.
An iron is your friend, get friendly with it.lol
I suppose I do all kinds of bad things but can't think of any right now, that is one thing getting old does for you, you can't remember!