i would rather photograph strangers than friends or family.
friends and family have expectations which always exceed what someone is willing to do
i often see someone and say, hey would you mind if i came by and took your portrait ... don't bother
with saying how they are interesting, or are good looking or any of that, people are ALWAYS self conscious ...
if they ask ... "why me, ... bla bla bla " just say you like taking portraits ...
the worst they could say is NO, right ?

getting them to say yes is the easy part ...
making a portrait is part dance, part art ...
the dance part is getting the person to relax and pose or not pose or whatever ...
thats the art of it too ...
the only advice is to have a conversation with the person to try to relax them, compliment them, make a fool of yourself,
i have found opening one of those compact coiled reflectors and having it open up smacking you in the face, or looking like you don't have a clue helps ...
then take their photograph ... it takes practice ... and once you do it a few times you will be pretty good

don't bother with email address &c just drop off a print the next time you see them and say thanks.

welcome to apug!
john