I meet many magicians (professional and amateur) who tell me that they don't want to script their routines because they want to improvise and be spontaneous. First, to improvise you need to have something to improvise upon - this is called a script! Second, this is just laziness. If you want to be different, make your routines uniquely your own and feel the satisfaction that comes from real work - start scripting your material. This does not mean a full word-for-word memorization and delivery, but it does mean that you thought about, and wrote down what you want to say. Be sure to memorize your routine's opening and closing line.