I'm a fan of slightly more detailed ones, it depends on your plans.
A few fun ones, "Do you smell something?" To cause a messy accident, "Looks like rain," for a wet one, stuff like that.
Or, if you prefer more direct ones, "Did you have an accident", "Do you need a change?" Etc.
(For other stuff like crawling, bany talk, etc, I can come up with stuff or you can.)

Go ahead come up with a name, I'll send you a brief description of my character in a minute.

I love it!
Should I just make up a name for my character?
Also, should I just be simplistic with the triggers like 'wet' for peeing, or be more complex?

Ooh...
Well, since you're letting me pick, how about this?
There's a pair of adult step siblings, (Say, college age,) one of whom (Me) is slightly older, and has always been bossier, the parent's favorite, and more popular at school. Over a long break, though, her plans with friends fall through and, with nowhere else to stay, she asks if she can spend the time at your character's house. You take this as a chance to get a little revenge, kindly send a mix tape of road trip tunes for the drive up to your place that's been layered with a few simple hypnotic commands, and once I arrive I'm all programmed just how you like for a humiliating visit. (I prefer hypnosis to be the "Trigger word causes an effect" variety, it's up to you whether you want to be overt right away, or whether you want to pretend that you don't have a clue why I'm suddenly never able to make it to the potty in time.)

Those all sound great!
I'll let you pick which one you want to do the most, and I'll be game to play the Dom.

It depends on what you want to do, but in general I like to play an unwillimg sub. Depending on your interests, kidnapling, blackmail, or hypnosis triggers can be fun, an old-fashioned "Dare/bet gone wrong" story is always cool, and anything where an authority or caretaker figure (like a babysitter,) gets subverted and made to act like the baby is always fun.
I'd be up for more of an "Adventure that happens to include diapers" plot as well.

Like Oc's? Yeah I can do that.
What kind of plot do you have in mind?

Would you be up for a Roleplay not related to any series in particular?