I saw SysAdMini wrote the following guidelines at http://www.malwaredomainlist.com/forums/index.php?topic=4003.0
-use "format code" to structure code
-use a second decoder tab to resolve "replace" instructions. you can do this by "eval(some_replace_instruction)". Now code is much more readable.
-transform DOM functions which Malzilla is unable to manage (getElementbyId, document.location.href)
However, the guidelines is limited to Malzilla.