Does this sound familiar? I have often explained to players how they should shoot while we're on the court and they're shooting and I'm rebounding for them. I show and tell them how to shoot and many times I hear players say, "but I'm more comfortable shooting like THIS". How do you respond to that if it's clear that their shooting mechanics are not good enough or would improve if they did this or that?

It depends upon what "this way" means and how much the mechanics are out of whack. If it's something blatant that usually catches up with a player at some point. They might be able to get away with it at the lower levels where the competition isn't as stiff, but when the real heat comes down, their shot is exposed.

Not sure what level we're talking here, but tracking some shots taken/shots missed might drive home the point. I usually would get with the parent and offer to work with the player on the side, only tweaking one thing at a time. More often than not the player wouldn't practice on their own and ended up slipping back into old habits.

It's the same with golf or tennis. I played a lot of tennis as a kid and won quite a few local tourneys. Parents hooked me up with a tennis pro and he changed my swing. Felt really uncomfortable, so I went back to my old swing. In the end, I could only get so far on a regional level.

Same with my golf swing. Took a pro lesson, he tweaks my swing, it feels uncomfortable so I went back to the old swing after a few months. I still have my day job and missed out going on tour.

I'm coaching 16-year olds now. One thing I tell players is to keep both shoulders straight when they shoot, many players will naturally turn their upper body and shoulders as they shoot. I can tell a player to keep his upper body and shoulders straight and paralell to the basket, SHOW them how to do it - they nod and say yes, they next time they shoot they still turn their upper body. I dont get it

I run into the same problem. It's tough to get kids to change their shot. And using the word "adjust" can work better because nobody wants to "change".

Some kids you can sell and persuade and will have the discipline to make adjustments. Others won't. They need to realize that if they want to get really good they need to adjust. They might get worse for a little while. But if they adjust, next year and the following years they will be better for it.

Now regarding the squared stance, maybe they revert to the staggered stance because it is more natural? And maybe a better way?

I was taught to square feet and shoulders to basket. However I believe that originated from the 2-handed shot 50 years ago and is still around in coaching. Now we all shoot with one hand and the squared stance is not very comfortable. I know Rick Penny, Tom Nordland, and a number of other shooting coaches teach a staggered stance so your shooting foot is a tad ahead and your shoulders open up a little. It's more natural and comfortable. That's what I teach too although I'm not a sticker about it. I realize that every player is different and what feels natural to me may not feel natural to another person.

So as long as they shoot the same way every time, they ball rolls off their fingers the same way each time in a straight line, and they get sufficient arc on their shot... I don't care too much about elbows in/out, exact stance, etc.

If you want i could probably dig out video clips about the squared versus staggered shooting stance.

Sure

I looked around and I could only find a good video on the DVD that Tom Nordland sells. He does a good job demonstrating why the stagger is preferred. The other free videos I found mostly just says "shoot like this" and doesn't explain why. Sorry I couldn't find what I had in mind.

Here are a few articles and a video about the subject:
https://onemotionbasketball.wordpress.com/2013/02/15/myths-of-shooting-pt-3/
http://basketball.stack.com/skills/shooting/ray-allens-textbook-shooting-form/
https://www.youtube.com/watch?v=R2dPp3JBLu8

Thank you