I've found a lot of instructions where people do RI or color flow on wax paper (so that you can see your design underneath and trace it) then transfer it to a cake. But what about transferring it to cookies? I'm afraid it won't look as nice as doing it directly on the cookie.

What I'm saying is, I like the look of doing it right on the cookie, but I'd like to be able to trace a template for more complicated images. How do I make that happen?

The one draw back I can think of is that your RI image would be flat where as your cookie may not be perfectly flat. I always do mine directly on the cookie but they've never been super intricate. I know there are some people who are fortunate enough to have been able to invest in a projector which can project their outline directly on the cookie, much like what you're doing with the wax paper. However, if you were to do it your way, I might make the image I was creating a bit smaller than the cookie so that when I went to glue it with the royal (and I'd put enough on the cookie to create a seal) I also piped around the outside to create a border.