So with your saber grip, your pistol grip, and our Dai parry, you have a wide range of angles your sword can make with your arm. Should you allow the angle to happen at the wrist or in the hand?
I've taken to letting my sword rotate around my ring adn middle fingers. For the saber grip, you can basically grip the sword in your fist so that it makes a 90-degree angle to your arm. For the pistol grip, you let your index and middle fingers loosen and push forward with your thumb so the angle becomes flatter, from 90 degrees to 120 or more depending on what's comfortable for you. For the Dai parry, let your little finger and ring finger out a bit so that as you lift your hand back it can sink and make the angle less than 90 degrees. Don't let the sword get too loose in your hand and you'll be able to switch smoothly between grips and adapt as the situation calls.