Grab something around your house and start sketching! Why? The practice!!! I teach art at a local elementary school and I’m always, ALWAYS, asked how I learned how to draw. The truth is, you have to keep drawing get better. And that’s how I learned to draw.
As you draw your sketch notice the lines, shapes, and values of the object you are drawing. Pay attention to the little details that define your object. Keep drawing and having an inner dialogue with yourself about the elements of art that make up your object. If you need to refresh your memory about the elements of art awesomeartists.com has some great downloads.