Go position
Glenn-sensei (and I think Suzuki-sensei) both say to have the go facing straight down as it enters the water, then to turn the go as it breaks the surface to keep bubbles from forming.
Ula prefers to keep the scoop at a consistent angle, 45º facing upwards.
You have a perfect edge to “cut” the water with, the corner of the bottom of the cup. Cut through the water with it, then keeping your hishaku at the same angle, let the water rush into the cup until it’s filled. Then you can continue going into the water.
On coming back out, Glenn-sensei particularly dislikes “dumping” water once you come back out, e.g. if you need a just a half scoop. It’s better to turn the go as you exit the water so you trap the perfect amount of water, without letting it flow out of the go once above the surface.
Elbow position
Suzuki-sensei says to bring your elbow to your side, then open your elbow out to start the pour. Finish the pour with your wrist.
Sugitani-sensei says the opposite! (I prefer the Suzuki-sensei way).
Use your whole body when scooping water. Don’t just extend your arm forward. Keep your kamae position and lean forward with your heart.
Don’t bring your elbow into your side (Suzuki-sensei way). Go straight from the kama to pouring the water, elbow following naturally.