BC - Every cartoonist should find a place where he or she can draw lots of different kinds of people.  This should be someplace where you can sit comfortably and quietly while people meander past.  You don't have to go every day, but the more you do this, the better you'll get!  The easiest place to see lots of people, especially for younger cartoonists, is at school.  Other places that work well are malls, coffee shops, sporting events, and flea markets.  This brings up another point; drawing people will also attract people!  You may find yourself surrounded by on-lookers!  This sometimes can be a little uncomfortable, but it is just part of being a cartoonist!