But at the risk of "being indulgent" which is one of Simon's trademark negative comments about a singer, I just have to join the fray.
One of the main lessons I get from watching the parade of singers each week is this. They have to be memorable. Even the people who did those embarassingly terrible auditions in the first week of the show had that right. They were memorable. (They got on TV, didn't they?) My gosh, the Pants on the Ground guy became an Internet star. At the final show, one of my favorite parts is getting to see those people for another 5 minutes.
I'm certainly not advocating that you strive to be a terrible presenter. Clearly that is no way to get invited back or to build credibility.
BWe're talking about entertainment.
Delivering a good presentation, just like singing a good song is not enough. You have to provide something that gives you an edge, add some color, add some flavor, mix in spice, emotion, and energy. The leading singers in both the men's and the women's competitions had something about them that went beyond their singing voice.
We all remember the big guy who's wife had a baby during auditions. We noticed the woman with the dreadlocks and the great voice.
Simon talked about singers who were forgetable over and over. Randy said things like it just wasn't there for me, dog. Ellen tried to be funny when she said essentially the same thing, there's nothing unique about what you did. And Kara talked about the need for singers to find and convey their own unique style.
Presentations are just songs without the music and the band. But there are plenty of judges - every single member of your audience. So make your next presentation memorable and authentic and you'll be invited back.