Okie, so I do have a bit to write for this one since I just took a pastry class featuring croissants and felt the background knowledge was really helpful. I had tried this technique for making the butter packet in the past and it didn't seem to work as well for me as the "mushing" technique. This is where you take all the butter and mush it in your hands until it is a consistent texture throughout and then flatten/mold it into the square. I didn't know this before I took the class but it was easier in the end to try to keep the rolled rectangle as crisp and strait as possible with squared edges. One helpful tip was to roll diagonally into the corners more often than in a straight line. If at any time in the process, the dough is bouncing back, let it rest for a few mins. Also another good tip was to keep an eye on any butter cracking along the sides while rolling, this means that the butter is too cold so you'll need to let is sit for a few mins.
In the class, the pastry chefs were using box cutters instead of pastry wheels, I thought that was a great and inexpensive way to get the job done. Keep an eye on any air bubbles while you roll and use the knife to slit them so the air releases too.
Overall, this was a great recipe. My husband thought they produced a flaky result but was a little less buttery than expected. They were really yummy warm from the oven!