I belong to three guilds one small, two large (over 100 members). None are registered as non profit. We have sales, raffles, and have quilt shows. We aren't registered as anything to state or federal. All three guilds have a designated all day sew day once a month for donations quilts. Or kits made up to take home to work sew and turn in. We have several lawyers and one retired judge as members in the larger guilds. And the mayor's wife is a member of the smaller guild. I guess you can make a guild as formal as the group wants it to be.