"I write a good amount. I've been gathering up a backlog of stuff and maybe I'll do something with it someday, but I don't want to talk about it just yet because that would jinx it"

Macaulay Culkin is revealing his desire to compose, however is reluctant to talk about it. He has actually been collecting ideas and material, however is not all set to share them with the world. He understands that speaking about his plans could be a jinx, and he does not want to risk it. He is most likely feeling a combination of enjoyment and fear, as he aspires to share his work but is also familiar with the possible risks. He is taking a careful approach, and is waiting till he is all set to share his deal with the world. His quote is a tip that it is very important to make the effort to prepare and prepare prior to taking a huge leap.