and most importantly, that you retain copyright and laying out the license that you grant with the prints you supply. Doesn't matter if it's your mother or brother or whatever as customer, rights need to be nailed down (duration, resale, sublicensing, replicas/backups, display, etc) precisely even if you're ultimately generous in what you grant.
When I do photography for friends, I sign all rights over to them. I can't see the point in keeping hold of the copyright to images which can never be of any value to me.
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.