It is always so easy to slip into the habit of drawing what you think you see, rather than drawing what you actually see.

This could be a correct perspective if I was sitting a good metre or so below this woman.
A perfectly reasonable sketch except when I came to add other people in I realised that they would, if drawn in correct perspective, be scraping the roof of this alley way of shops. The rule of thumb is all heads of people, near and far in a sketch, should be on the same level unless you are sitting way above or below you subject.
This is the second version of my sketch this morning after I realised the woman’s head was below the jars of honey, not above them.

Sitting at the same level as this woman this is the correct perspective as she is sitting at the same eye line as me.
Side by side.