This AppleScript, which I usually invoke from the Applesripts menu, does this by offering me a choice of alphabetically-sorted names that I can further modify, or create my own name. It is based on snippets and ideas I have gleaned elsewhere.
[robg adds: Copy and paste the text into a new script editor document, and save it as a script in your user's Library -> Scripts folder (create this if necessary). Then select a number of files in the Finder, and choose the script name from the AppleScript menu. You will be given a list of the selected filenames, from which you can choose one as the basis for a new folder name. After naming the folder, the chosen files will be moved into that folder. I tested on a duplicated folder, just to be sure things worked!]

