Are you an artist? if so, how do you apply shading to your drawing, painting, sculptures, ect.?

Im having such a hard time giving my artwork a three dimensional look. Is there a easy,fast way to apply shading? Would you be willing to share your technique? How do you decide what type of shading would look the best? i don’t understand cross-hatching, but i love how it looks, gradiation isn’t easy to appy either. Would you be willing to share your process with me? any feedback is greatly appreciated, wiether you are self taught or have a degree.