How do I assure that all files from a shared HFS+ drives are always writable by all users? I have a shared drive on a Mac and I keep having problems accessing different directories.

For example, while logged on the server as root I create a new folder aaa on this drive.

Now, I discover that a normal user cannot write to this directory.

Is there a way for me to change the default permissions/ACLs so I prevent this from happening in the future.

I am looking for a one-time solution, not running chmod or chown each time.

Details: 


it seems that root is not member of staff group because when I do ls -l I see group _unknown listed for files created by root.
By default the files do get only xr write for the group (drwxr-xr-x), how can I change so the group will have the same rights as the user, by default?
Can this be changes per mounted volume or directory, or changing this would affect the entire system? Risks?
Get Info on said drive and checking Ignore Ownership might help you.