As for portraits??? Back when I was in art school I'd get these nice bound sketch books and fill 'um with sketches of people... Some folks I'd spend more time with than others and they'd end up framable but mostly they were quickies... Of course, in art school, quick is in... When we were drawing from nude models they'd run you thru exercises where ya' had 1 minute, 2 minutes and 5 minutes to draw what you could loosens up yer arms real well on the 1 minute ones...
But I'd find places where people would sit long enough fir me to snag a drawin'... There are thousands of these drawing in those sketch pads... But I have done a few portraits of freinds and given them to them... Mostly charcoal or pencil...
Only drawin' I'm doing these days are engineering drawings for buliding permits...