This modern motion ends with the shooting arm pointed at the basket and the guide or support hand held back. To test this out, square up to a target and bring your hand up above your head to where you would bring a ball to shoot. Notice where your shooting elbow naturally goes. If you shoot this way, your motion will be angled to the side and it will be hard to be accurate. Try it both ways and find what is most effective and comfortable for you.
Pressure affects everybody.
As you take your stance to shoot a free throw when a game is close or the crowd is very vocal, you will encounter pressure. If you doubt yourself or analyze too much, you'll increase the pressure. The opposite of doubt is trust. First, realize it's important to have an effective free throw motion so you have something to trust. Strive to develop a free throw motion that really works.