I would do assembly line style for each week and at the end of a week, "finish" the bows. After about 2 weeks or so, you'll see how much time it takes you to complete a set of bows. Plus you don't want to get down to crunch time and have to 'finish' all 400 bows by doing the last step over and over again. But then again I get bored doing something over and over repeatedly in one sitting. If that doesn't bother you, then you should be fine! Congrats on your first and BIG order!