First he determines if the smell is worth rolling in. The answer is always yes.
Then he works a back and forth wiggling motion to maximize the smell to fur ratio.
Followed by a good head grinding action to solidify the worm smell in his fur until the next bath. (Those baths have been occurring more frequently as of late)
And one last roll for the sheer joy of it.
He has also taken to trying to roll in bird poop when we are on our walks... as we are walking. It doesn't matter that we aren't stopping. He hurls himself into the concrete for the chance to add Eau De Poo on his shoulders.