The images that I am working are not smooth

The lines of the shapes or drawings or images that I am working on are not smooth. They are very rough, jagged and crooked. How do I make them smoother?

Can I get an answer to this please?

You may have OpenGL enabled. Open your preferences and go to the OpenGL tab. Go down to the Real-Time Antialiasing section and disable it.

Also, you can adjust your pencil and brush smoothness and contour optimization in the Tool Properties panel.