You probably have read and followed a lot of tutorials on drawing hands. Chances are big that you more than once read or heard the advice to look at your own hands whilst drawing as you have your models available all day long.
This is a good tip indeed, but you may struggle with drawing hands anyway. The biggest problem of looking at your own hands whilst drawing is that you are looking at a 3D object whilst drawing a 2D one.
The core of your problem could be that you unknowingly drawing from two points of view at the same time. This could be the reason that the result you get is not what you expected.
My little tip is obvious: close one eye when you look at your model.
Have a great time drawing!