Hand quilting or machine quilting?
If I am using chalk I mark as I go. I once made the mistake of marking out an entire quilt with a ceramic lead pencil in white for hand quilting before basting. Most of my marks had rubbed off to the point I couldn't see them by the time I hooped the quilt. I had to remark as I went.
Now I have a rack and quilt on a LA so chalk marks tend to stay a little better but I still give them a quick spray with hairspray to help them stay put and not rub off. If my designs are based on the blocks, or I can easily measure to continue the design, I mark as I go. But if I have a large design that spans larger than my throat space, I mark before loading