Start with simple subjects to draw. Here I will help you improve your level of art.
Make sure you sharpen your pencil well before you start, preferably with a razor. You need at least 4 or 5 types of contrast when drawing, in fact it is better to use a variety of degrees of darkness and lightness in your work. Here I have shown you what I mean.
Choose a stone. Look at it carefully and examine it from different angles. The feeling of having the stone in your hands and being able to touch it allows you to have a better understanding of its material.
Start with the general outlines, for example, start from the outside first, then draw the main lines of the interior surfaces. Keep it simple and don't pay attention to the different textures and patterns at first.
Then notice which side of the stone is darker and gradually add more darkness and then add details. Finally, if you like, turn the stone and if you see a texture or crack or a special depression or bump on the stone that you would like to have in your work, add it to one of the surfaces. You don't necessarily have to draw the exact same stone, you should be creative and add the surfaces you like to your drawing.
Watch the video and if you need any advice, ask me below this post or if you like, do it as a challenge and publish a post after designing it and tag me so I can see your post. I wish you all the best.