You have to get past the technique. When you are showing volume and form it's paramount to exaggerate the model and indicate what's close and what's far to punch up the illusion of depth. The white that you use on the tip of the nose cannot be the same white that's on the peak of the forehead. Nothinging can ever be the same. When it's too close to the same it's looks flat because of course the Human brain is used to perceiving space in a certain way. Even if someone isn't an artist they will know that something is not quite right. So, you have the technique down but that is not enough. You have to make a statement before you make your statement. Remember art is a language and there are rules speaking a particular dialect.
Remember, you can't bullshit art. It is, particularly when engaged in painterly techniques an excellent recorder of emotion. The real you comes out. Whatever you fear, hate, love, etc., will crossover.
This is a life long lesson that if you are prepared to learn until the day you die is not worth the effort. I've got 45 years under my belt and I'm still learning and creating new things.
Without work nothing prospers.