I am also including the tips that Aparna had mentioned in the procedure. I followed this and helped me achieve the best Classic Croissants I could possibly make.
Ensure that your butter is cold – cold enough that it is pliable enough to smoothly roll out; not hard (or it will break) or soft (it will melt). If the butter is too hard and breaks while rolling out the dough, you will not get the layers in the croissants.
Do not over-knead / develop the dough too much, too much gluten will not help during the lamination process. The lamination process itself is a kind of stretch and fold anyway and will strengthen the dough. So keep to the 3 minutes the recipe says. You want soft dough, not an elastic one.
When you cover the butter square with the dough, make sure you seal the dough well, otherwise the butter will leak out when you roll out the dough, and there’s no way you can manage to put the butter back in. You will also end up with butter leaking during the baking.
Always, always make sure your dough and butter inside it are cold. I cannot stress the importance of this enough. Once the butter has melted, it is difficult to get the dough to produce layers because the dough tends to absorb the butter and will make greasy croissants. So, while working with the dough, or when rolling it out, if at any point you feel the dough becoming warm and soft, put it back in the fridge immediately. Also work as quickly as you can so the butter stays cold.
During the lamination of the dough (rolling and folding repeatedly), chill the dough in the freezer and NOT the fridge. The overnight refrigeration is to be done in the fridge NOT in the freezer. Resting the dough is an important part of the croissant making process.
You also need a lot of patience to keep rolling out the dough with just enough pressure to stretch it. The rolled out dough before shaping should be somewhere between ¼” and ⅛” thick.
Make sure your dough is shaped with straight lines and square-ish corners. All the time you are rolling your dough out, keep this in mind. This way you will minimize waste of dough. More importantly, the edges where there is no butter would get folded in during lamination and affect your layers. So trim off those bits if you have any of them.
Keep lightly flouring your work surface (not too much), just enough to keep working smoothly without tearing the dough. However, dust with a light hand or you could end up adding more flour than desirable.
Do not be tempted to fold more than three times. A fourth fold will give you more layers, but thinner butter layers between them, and your croissants will not puff of as much as you would like them to.
And most important, as funny as it sounds. If you like to and do wear rings on your fingers like I do, take them off while working with this dough and the dough will thank you! Rings have a habit of inadvertently tearing the dough. If the butter comes out, patching it up by dusting a little flour can help but doesn’t always work.