Sketching can be as complicated as you want to make it.
Firstly, find the idea OR you may have the subject in front of you.
Next, put pencil to paper,
and when you are happy with it,
start to add paint.
Ending up with a piece of art that could either be Sold OR mostly with sketching,
just saved and shared online.
The point I'm getting to is, keep drawing and painting -
your hand/eye co-ordination will improve immensely over time.