Squadron patches

Hello everyone, new to this forum and hope to get some help. I'm working on a F-15 repaint of one of our aircrafts and cannot figure out how to add squadron and command patches on the repaint. I can get lettering and tail numbers okay, just don't know how to put the patches on. I've read several repaint tutorials and cannot seem to find any specifics on how to do patches. Are these items hand drawn or are they copy and paste from some source. Any help is appeciated.Oh, this is my first attempt at a repaint.Thanks, Wing