I'm happy to call croissants a staple in our house. I'm even at the point where I can vary the dough and fillings to get fun creations that we all enjoy. I got to this point with a lot of practice and two significant events. About 5 years ago, I took a croissant class with Tad at La Chatelaine Bakery (@LaChatColumbus). Tad is a masterful baker, one of my favorites ever. His croissant method produced exquisite pastry, but the method was taught to us with some rigidity. *This* is how it's done. I stumbled a little after this with little success. The next significant stop on this journey was years later at another class at @The_Commissary with Aaron Clouse (IG @clouse11). In this class the dough was more enriched than in my previous class (some milk and butter) and there were physical variations in the folding. Some used a sheeter, some rolled by hand. The combination of classes led me to conclude there is a much greater range of methodology and recipe that will yield an amazing pastry.
My recommendation is to practice using any prep out there: Bouchon has a good method and many bloggers have stolen it and republished it - but it's easily available. Another well detailed prep is from King Arthur. BUT, I gather you'll need to use a class to go the distance. Take either mentioned above, but I'm a little partial to Aaron's (sorry Tad!).
A few examples of my work below. My benchmark numbers:
X grams butter,
X grams liquid,
1.67 X grams flour.
After a bifold of butter, 3 turns, scale each to about 75-100 g, roll, sit them in the fridge overnight covered, then a looong proof the next morning, ca. 2 hours, glaze with yolk/milk and baking at 375F for about 20 minutes (convection).
Classic and nutella. Dough using mostly milk and 10% whole wheat flour.
Similar but no whole wheat in flour bill.
Also all unbleached white, no wheat. Nutella on left. Interesting that the nutella didn't crush the internal structure.