Who are you?

That is a question that you need to get into the habit of asking your characters. Find out who that are. Not just the ones that feature prominently in your stories, but the bit players that walk into and out of the scene with hardly a notice of their existence.

They are noticed, however, and that is why you need to ask them "Who are you?" An in depth interview is not necessary, save that for the characters you will have in the action the most. Just ask a basic mug-shot profile of the wayward wanderers and then create a mugshot file for them.

Record a general description such as:

Bum in street
Held grubby hand out to hero, eyes were grey-blue in color.
Unkempt hair was a dirty straw color.
Had a scar on his hand that made it look gnarled as he held it out and begged for a copper halfpenny.

This kind of "Who are you?" questioning can be helpful later on when you decide out of the blue that you want to have the hero attacked by someone with a gnarled hand that they know from somewhere. You can look back through your character cards and find the beggar and expand on that character to create a living figure that your readers will remember from earlier in the book or series.