2) you need far more focus layers images than you think
And, what surprises a lot of people is that if your shot contains lots of information at or near infinity, you can benefit from having as many as two steps that are just barely short of infinity. Including steps at 50 feet, 200 feet, infinity is not a wasted effort when shooting f8 with medium FL lenses.
It's kind of counter intuitive, but in terms of the amount of lens rotation needed you can have relatively wide steps for nearby objects, but you need increasingly fine steps as you approach infinity.
And while it is possible to make a set of focus marks that will cover a range of focus for objects from nearby to infinity, there are often cases as with the tree shot where scenes naturally organize themselves in distinct planes, in which case just march your focus from important plane to important plane.
Oops, somebody just pointed out my old post which I had hoped would die because of the huge download was murdering my bandwidth! Look if you must, but please don't reply to that article which will top post it! But please realize that's the really hardcore solution. What didn't get sufficiently stressed there was that you need to test finely separated focus lanes near infinity.
PS, don't anybody think they can shoot that tree shot with a T/S lens.