Fold into thirds and roll out (repeat several times)

Next is the layering process. The dough starts out as a stack of dough, butter, dough, butter, dough. Now you fold it into thirds (like a letter) and roll it out to multiply the layers. You want to do the folding/rolling out process about 4-5 times total.

The trick is that temperature is important. Once the butter and dough are together, the butter should be slightly soft. Do one 3-fold. Gently roll out, trying to keep butter inside as solid layers. The goal is to avoid the butter breaking up into chunks. Take your time rolling it out, apply smooth even pressure.

Once the first 3-fold is rolled out, do another 3-fold, cover in plastic and refrigerate. From here on, you want to take out the dough, let it warm for a minute, then roll it out, do another 3-fold, and put it back in plastic and back in the refrigerator. Sometimes chilling after every fold is not needed, you can do 2 or 3 folds and roll outs in one batch. But, if the dough and butter warm up too much the dough will start to stick to everything and the layers of dough and butter will start to pull apart from each other.

In the end you want to do at least 4 fold-roll out steps. If you see chunks of butter layered between dough, you're rolling it with the butter too cold. To fix, let the dough warm up slightly longer and roll thinner before folding (use flour to avoid sticking).

In the photo you can see that I have a couple spots where the butter and dough ripped apart. Don't worry if everything is perfect, it won't matter in the end.