As you've just begun I'd say simply practice. It often help to draw a quick sketch of your idea. Capture the key elements you want so that you can solidly remember what you originally want to achieve. Remember you mold and sculpt the shapes, don't let the shapes sculpt themselves if you have something else in mind. Also study the world around you. Train your eye and your mind to see how forms create the things you see, Study how light and show work to create those forms.