This page provides a tool for finding sets of scrabble tiles that can be used with The Jerx's Ascrabbological Sign trick, but for other sets of words (i.e. if you wanted to use the same method for divining something other than someone's astrological sign).
Note that this tool assumes that the performer has control over the choice of words and can avoid words that cannot be distinguished solely based on the letters that they contain (e.g. anagrams). If that is not the case, then the very similar Alphablocks tool solves more-or-less the same problem but works with an arbitrary list of words (e.g. supplied by a spectator).
To find a solution for some other set of words, choose your parameters and provide the set of words you wish to use below.
There's a reasonable chance that this tool doesn't do quite what you want. If you find yourself saying, "Yes, but I want a solution where..." then please get in touch and I'll see what I can do to extend the tool or otherwise find a solution that meets your needs.