If your string is properly positioned, it should be held diagonally across your palm, looped over the back base of each pinky finger and thumb.
One way to think about the proper shape is a large diamond in the center connected to two triangles by its top and bottom angles. The other two angles are at your index fingers. The bases of the triangles are the parallel string segments between your thumbs and your pinky fingers.
Some guides will use “little finger” instead of “pinky finger” and “forefinger” or “pointer finger” instead of “index finger. “[11] X Research source
This opening is sometimes called the Index Opening.