Welcome to the group

Can you describe for me what makes you feel welcome in a new group? (SCA, school, work, girl scouts, church, AA, any group you had to walk into when you didn't know many people there is fine.)

I was wondering about this, because it's come up in a couple of conversations recently. I've been trying to remember why I felt welcomed and comfortable in some groups but not in others. I know there are lines between "off-putting", "welcoming" and "swarmed by mad-eye'd cultists", so I'd like to take a stab at defining them.