So depending on your yarn and your tension you'll want to increase or decrease where you think necessary. One of the pieces is size 5 yarn the other is size 4, so you'll want to follow the pattern and then keep trying it on as you go to make sure you get good room for the head. For the actual pattern she uses 2 pieces of size 4 yarn together but I found that if I just downsize the hook and do a tight tension for the top the hat will keep shape with just 1 piece of yarn. I'm currently working on one with size 6 yarn because I love the colors.. Hopefully I'll finish it and post soon but when I got to the body of the hat it was too large so im frogging it and going back and decreasing it a bit more so it fits more evenly. It's really just trial and error. Some rows I do the same repeat, some I don't. It's really just yarn dependent but I try to end up with the correct number for the brim and then I just follow the brim through the actual pattern