Let me elaborate. When we newer magicians write patter, we usually hit it from two broad angles. One is the expository angle. This is where you just say what you are doing. I think this is both the easiest and safest patter to write. But even here, there are dangers. Done incorrectly, it can be deadly boring, confusing, or both. The second is the storyline. This is very tempting for newer magicians because it seems to give your routines some gravity. But proper story writing for routines is hard without some deep writing skills and good theatrical training. Done poorly it can look silly. One on one, it can be OK and cute. It is harder to tell stories, without adequate training, for larger groups. (I used to tell a female assistant, when I performed Red Hot Mamma, that the cards were guys, and the one she picked was blushing. Cute for one or two, but try this in front of 15, and it looks silly. And this is just an example of a slight variation of the normal plot.)
But beyond just the words is the whole structure of the effect. The words should guide the spectators down an intellectual path to the final effect. But it is the structure of the routine that makes the path. On the Cafe we had a debate over whether we should ever repeat an effect. The stock answer is no, we should never repeat an effect.
You should go a read that thread and read Whit Haydn's responses. He clearly argued, not only is it acceptable to repeat effect (using different methods,) but it is often necessary to strengthen a trick. Magic, he says, should lead the spectators to the horns of a dilemma. You want to destroy any naturally ocurring tendancy to try to figure out how you did it. They should end up saying, "It can't be magic, but there is no other explanation." Here is an example of a spectator’s response to a trick. "I thought I saw you put that card in the middle, but it ended up on top. Maybe you did not really put it in the middle. There, I solved it. Dumb trick." Recognize this? It is a one-phase Ambitious card routine. Are you going to follow the rule not to repeat? Of course not. You will go to phase two and even more clearly put the card into the center and make it go back on top. "Well, maybe you did a card switch," they think. So you do phase three, and let them see the signed card go into the middle. Still back on top. Now the spectator is tottering so you go in for the kill. You bend the card, you put it into the middle, and it still comes back to the top. "It can't be magic, but there is no other explanation." So where does patter fall into this? Well, it could be expository. Keep in mind though; you are intellectually killing the spectator. You can write patter that makes you look great and the spec look like an idiot. Ever see that? It can happen without even trying. Or you could write patter that softens the bitter pill, make it enjoyable, and make them love you. Think it is easy? It is not. One big complaint that I hear is that magicians come off like egotistical jacka**es. But study Whit Haydn's routines, Chicago Surprise (which includes essays on what I am, poorly, trying to say here,) Mongolian Pop Knot, and the Comedy Four Ring Routine and learn how patter can be used to make the audience love your magic and you, even as you fool them. In his ring routine, the helper fails three times to get two rings apart, but since the magician never notices it, he is filled with effusive praise, hugs, and leads rounds of applause for that helper, who leaves the stage the hero. At best the magician comes off as nice; at worse, he comes off as a buffoon—but a buffoon with a twinkle in his eyes that say, “We all know I was joking and we are all having great fun.”
My cups routine is mostly expository with built in impromptu lines for things that happen. Although I am new to street magic, I have taught for twenty years, I give sermons, and teach three-day workshops. I have some skill with groups and hecklers. I can anticipate things that might happen, where confusion might reign, or where boredom might set in. But even so, my patter develops from my experience and I modify it everyday. But it is good that I had as a basis a routine and patter that had been used on the street for twenty years. I change the patter, but I pay attention to what I am changing. The original patter was designed to facilitate a certain flow to the routine. If I just start changing the patter, or even worse, just do it on my own with no experience, I end up with an illogical and less than effective routine.
Write your own patter, if you want, but try to base it on the way classic routines were done. BTW, don’t think a demo video on any website provides professional patter. Change that at will.