For the first few months after learning the LBRP, I did only the banishing, like most people.
I decided one day, at work, to try the Invoking form. So I went in the bathroom at work and did, what I thought, was the LIRP. I drew the pentagrams the opposite way I would with the LBRP. And in my visualizations, instead of "banishing" (sending the energy out) I visualized energy coming in.
I was jacked up! Lots of energy hit me. I felt like I had drank a spiritual Redbull. I was very charged. My boss was happy, as I was full of energy and moving with a purpose.
When I got home, I saw that I had actually drawn Fire pentagrams. It all made sense.
This got me thinking about using the different pentagrams for different reasons, and utilizing this "stone of the wise". I've only seen it referenced in one book, to use the different pentagrams to achieve various goals throughout your day.