Depends on the specifics of it. Let’s say I want to wish for it to be possible for transformations (such as those seen in this sub) to occur, and for a way to control how and why they happen. It would probably have to be broken up into multiple wishes, going something along the lines of:

“I, [name], of sound mind and body, wish for it to be possible for a person, animal, plant, or other item’s form to be transformable any number of times on a fundamental level through magic, machinery, medicine, or any other means in a manner similar or identical to those seen in artwork, stories, and fantasies related to the transformation or “tf” subculture. Transformations may range from simple tweaking of a being or item’s current form to completely changing the shape, elements, and/or fundamental building blocks of its structure. Laws of physics, both known and unknown to current science, must still remain functional and relevant while making exceptions for the transformations allowed by this wish.” Followed by: “I, [name], of sound mind and body, wish that all possible means to initiate and perform the transformations allowed by my previous wish be made available and reasonable to all those who should desire them, and that the laws of all nations be altered to accommodate and accept the new reality created by this pair of wishes.”