There are two basic ways: Manually, or with an anagram generator
program.
Some purists prefer to anagram manually with a pencil
and paper or with Scrabble tiles. Most other members have anagram software, like Anagram Artist, Anagram Genius or Wordplay (see Anagrammy
Links & Resources Page).
The main advantages of using a computer program are speed and the generator's word list. They will generate hundreds or thousands of anagrams in a minute or two. Most will be meaningless and one still has to do some work to find the most appropriate ones, by selecting keywords and anagramming the remaining letters. the end result must read well, be correctly spelt and have acceptable grammar.
There are also anagram checker programs that determine the
difference between the letters of the subject and those of the
anagram-in-progress, so that you know how many of each letter
are still available for use. These are very useful when creating long anagrams.
Read more about creating long anagrams in this article: The Art of Long Anagramming.
Many of our regular contributors have developed anagram generators
and checkers themselves. Use
this link to find out more.
There has been debate here as to whether using an anagram
generator is "cheating". Sometimes they will quickly
reveal a great anagram, but there is always a modicum of luck
and a lot of skill needed to find the best anagrams. The consensus is that it is not cheating.