When making a character, I usually tend to follow the sheet that D&D provides, and it has a slot for ideals. This can be pretty much anything that your character wants to be like, for example, wanting to be nice to everyone they meet. That’s a pretty basic example, but they can also be more complicated should you so like.
This is shown in one of my characters I have, who has the ideal of respecting the laws of nature, not always the laws that are made. Now it should be said I usually am the Dungeon Master in my group, which makes it so that I can be pretty much anyone in the world I created, this character is one of those. He looks to how animals treat each other to see how he wants the laws to work, of course they don’t work like that, but usually he doesn’t care about that.
One of the interactions that this has caused, was when someone stole a thing, and he saw it as perfectly legal, as animals sometimes takes things from one another. That’s not how the “police” or the law enforcement equivalent of medieval times saw it however. Luckily for him, he wasn’t the one who had stolen that thing, but he did get into an argument about how it worked with the other parties. Of course the one who stole the thing was on his side, but the others weren’t really that.
This is an example of how a thought through ideal can make for interesting roleplay, and not only that, it can also be pretty funny to imagine what situations they make themselves. It can also be a simple thing like for example wanting to have a water canteen with them at all times, it’s up to you really, but it can be really fun to do something creative with it.