Michael Jordan, the famed basketball player, has a quote that fits this situation well:
PRACTICE LIKE YOU PLAY - in other words, practice how you will do it in person.
I often think of a premise, and then think of what I want to get across. I come up with a presentation, sometimes...actually, often, I write it down.
I think read the script while I am doing the effect - and just as often, I need to trim the fat to make the words and the effect run together smoothly.
I then have a "presentation", however, all my presentations have to have room for the audience...the responses to their questions, their jokes...their personality.
So, even though I have a script - it is a loose script...as I have to be able to react to the situation. Aaron Fisher once compared it to Jazz music...I know how I will start...and end...and the middle is improvised...if the audience isn't involved...I know EXACTLY what I will say...if they are...I can stray from my script to meet the needs of the participants to ensure they ARE part of the show.
I think bad advice is - I just make it up on the spot - sorry Mr Madman - but I find guys like you to stumble...have unclear presentations...and that is part of magic malpractice. Your words are filler for the effect - and people recognize that.
Good advice - film yourself, as many of the guys said above - and test out new approaches to define what works and doesn't - but PLANNED, not unplanned.
I also recommend asking people - and thinking of ways to communicate life's concepts and issues in your effects. This is how you can create interest, and sometimes emotion.
Don't watch other guys and steal - but watch other guys and see how they present things...and why - then use that concept to approach your stuff. Try to make your stuff your own - sometimes that is really hard...as the owner of the effect has thought LONG and HARD on how to present it - but try - because you may be able to find a way to present the effect that speaks to who YOU are.
Lastly, don't present it in a way that makes it corny - when you say words - pretend you are NOT doing magic...that you are communicating something about real life...saying the "Jacks are Spies that will look through paperwork to find your card" is more childish and corny than saying "these jacks represent the last place your looked...ever hear the saying, "ywhen you lose something, you always find it in the last place you looked - duh, why would you keep looking, when you found it?", but I realize that sometimes we overlook the last place we looked - look between the jacks - take a card, let's lose it - and then do a sandwich effect where it looks like you don't do anything - and the card appears between the two cards (Lee Asher has a great one from his lecture notes using Pulp Friction) - anyhow, even though that was off the top of my head...you can see how one is corny and childlike, and the other people can relate to and the magic illustrates your point....
wow...I said too much. Over and out!