Custom orders are not something I offer very often and I am very selective regarding what I'm willing to make and the time it'll take.
Most custom orders for pieces that are already in my repertoire are usually not an issue. However, requests for work that I might be interested in, but is not in my current repertoire will take more time that I could spend on work that I wish to do. This isn't to say I don't mind requests and challenges, but that if it isn't something I plan to make again in the future, it isn't the best use of my time.
If you have a design in mind that is outside my wheelhouse, please feel free to ask me if I know another artist who makes similar pieces. While there is no way I can speak for that artist, finding the right artist, one who makes what you're dreaming up makes more sense than asking me to make something outside of my interest. To be honest, work that is forced never turns out as well.