Thread: Basic but not always known.

A couple of days ago I was wading through archery clips on Youtube and came upon a clip titled "three common mistakes."
Well I thought to myself I don't think this will help me, I've been bow hunting for quite a few years, anyway long story short, I was wrong.
This got me thinking of when I was working in the firearm retail sector and some experiences of simple things that people did not know, even though they had been shooting for years.
Father brings son in to buy his first rifle, and I watch the young fella struggling to shoulder the rifle and look through the scope. I suggest that his son may shoot left handed "no way my son is right handed" the dad says. So I asked the boy to point with his finger at a spot on the other side of the room and then close his right eye then his left eye and asked what I kept your finger on the spot? His left eye did.
Another story was a fella in his late teens came in with his dad to tell me there was something wrong with his new rifle I had sold him. He told me he shot at a pig three times and missed each time, I told him it was probably operator error, to which the Dad jumped in telling me that his son shoots good. So after some questioning, it turns out he was shooting up hill, I asked if he allowed for the up hill angle, to which he replied yeah I aimed a bit higher. It took some time to convince both father and son that you aim lower for uphill and downhill.

Hoping to hear some more useful hints from you guys, I'm sure there should be plenty.