You may find it helpful to use tick marks to indicate distances. Tick marks are tiny marks you draw on your paper to indicate a visual landmark that you use to map out other visual landmarks as you draw. This is preferable to just eyeballing the distance and assuming you are correct. Tick marks help you create a basic diagram or structure for your drawing.
Diagram With Tick Marks
This diagram of tick marks shows how they establish the key points for your drawing.
Fill in the Tick Marks to Complete the Drawing
Once you’ve mapped out the proportions with tick marks, the details are much easier to add. Be sure to include your subject’s environment in your tick mark diagram. The subject’s environment provides additional reference points for measuring to achieve correct proportions.
The Young Horse Woman
Charcoal on bond paper
10" × 14" (25cm × 36cm)