You didn't specify what the purpose was. Skill? Patterning? For patterning, I use a big box and a roll or two of wrapping paper (like Christmas paper, giftwrap, etc.). Put a big, black dot (perm. marker) in the middle and use that as POA. It's gotta be at least three feet across though, or you won't get any information. Chokes are designed for specific patterns at 40 yds.
I seldom do it... only when I have a new gun or choke tube that I need to find out about.
If you mean practicing for SD, I don't have any idea.