This part may seem pretty redundant to you, considering that if you're looking into this site at all, you probably have a PRETTY GOOD idea of the ghost you want to make! Before you get into it though, I just want to talk about the many different options available to you! My Hunter/Smoker ghost has two human characters talking to each other, but that's not the only way to make a ghost! In fact, most traditional ghosts are set up like this.
A "traditional" Ghost is usually a girl of some sort with a small mascot-like creature as her friend. As such, her focus is primarily on YOU, the user, and not on her mascot friend, although they do still chat. Many ghosts are set up like this, with one main character and a sidekick. Sometimes the sidekick doesn't even talk! They just have a menu with functions the main ghost couldn't fit. Sometimes the sidekick is just a floating ball or a logo or even just a sign or a computer.
While you can't remove the sidekick entirely, you can make them invisible fairly easily, so be aware that if you want to make a Ghost that's focused on one character, you can do that! So if you can only think of dialogue or ideas for one character, don't write ghosts off yet! Kaito for example doesn't have a partner at all.
Here are a few "traditional" ghosts, with a main character and a small sidekick. Girl and Triangle actually fall naturally into this mold to an extent, which was why I decided to use them for the template.
Now, here's my Hunter/Smoker ghost.
Here, we have two full human characters who talk to each other. In fact, I eventually added Charger, so there are three separate characters who can talk to each other, as well as the user at points.
Here's another two person ghost. The basic point here is that you don't have to feel limited by the two character mold, or the main character/sidekick mold, or even the single character mold. Think about each format and decide which one will work best for you and the character(s) you have in mind.
Ghosts can also be very small or very large, so don't feel limited by the template's size either!
They can also be doing different things, like this ghost is in a hot spring (cap from here), so they don't just have to be standing around the computer.
Basically, this page is just to remind you that you don't have to follow the template's guidelines exactly once you have an understanding of how ghosts work. You can do a lot of different creative things with them!