Most commonly gifts are digital, such as drawings or short fic.

Physcial gifts that you mail to the recipient (such as a traditional drawing or painting, or more crafty things like a plush or cross stitch) are also allowed, although not everyone is comfortable giving their mailing address in order to receive physical gifts. They also cost money for materials and shipping, whereas digital gifts mostly just take time to make.

And don’t feel any pressure to send anything physical!  It’s really more of just an option in case someone wants to send something. No one is expected or required to do so.

A prompt is anything you want it to be! Though probably more along the lines of “X and Y character in the rain” rather than just “rain” (unless of course you’re really dead set on rain and don’t really care what else is involved 😛 ). Basically it’s to let your Santa know what kind of gift you would like. So make sure it’s something that you personally want to see/read! 

You can find last year’s wishlists here if you need inspiration or reference!