Start out with the dough of your choosing, wrap it up and let it rest in the fridge for about an hour. When you take it out, it should look like this:
Prepare your butter blocks - butter to flour ratio is exceedingly high, no lie.
You'll need a rolling pin such as this, a brush and a nice surface on which to roll.
I smoosh the ball of dough with my hands into a little square. Roll little "ears" onto the square, leaving a bump in the middle. Do not be afraid to use flour, the dough is intentionally soft to allow for the introduction of more flour as you turn.
Plonk the butter block on the mound in the middle.
...and fold the flaps over the top. Smoosh the butter out into a nice envelope looking thing. As 'B' said, "Start with a rectangle, end up with a rectangle; start with a circle, end up with a circle."
Roll it out about two feet by one foot.
Use the bench scraper to make the corners and sides square. This gets progressively easy with each turn, I've found. Fold up the bottom, if you've got an ookie edge, make sure that one goes in first.
Dust off the extra flour.
Then fold down the other third.
Do this two more times, with about 30 minutes of wrapped resting in the fridge in-between each turn. The last (third) turn as a book-fold. I do this once a week and it took me 6 months to feel proficient.
I owe my proficiency to the fabulous and glamorous, B.