What constraints do you have?

What practical concerns and limitations do you need to work within? Does this move need to fit in a limited space? What other PC moves might interact with it? How much time are you willing to spend on this move in play? How much time do you have to write it?

You're probably already aware of these constraints, at least at a gut level. But it can help to acknowledge them, and keep them in mind as you design your move.

The preferences, personalities, and quirks of your players are constraints, too. Keep your specific group in mind!