I think it all depends on your area, the type of soils you have and how large your garden is if it is feasible to till or not to till. We have clay and rock soils, so double digging would just result in very large clumps and rocks, unfit for any planting at all...even digging multiple times would yield the same thing. This garden has swallowed many, many soil amendments over the 22 yrs it has been used but nothing really changes the structure of that soil.
Add to that, the garden area is large and double digging would take forever to accomplish, even if our old bodies could do it. Clay soils are heavy, so turning them is no easy thing.
I have just about finished tilling our garden for planting and it has been tilled no less than 6 times already just to break it up enough to be able to plant into it...and even then it's still pretty clumpy. Good rear-tine tiller, good tilling action...but that soil needs worked up and well.
What we do to re-establish some healthy soil culture after all that tilling is to not disturb the soil for the rest of the garden season so the microbial, worm and insect life can settle back in. We hill up the rows, either mulch or place suppression cloth down, then seed the pathways to White Dutch clover. It grows quickly and provides soil and moisture retention, keeps the paths from becoming too compacted, attracts honey bees and other pollinators, provides good cover for worms, fixes nitrogen in the soil and suppresses weed growth, keeps our shoes and knees clean, is low growing so it doesn't have to be mowed down and makes for a pretty garden.
In the fall, when the harvest is done, we till the rows again and reseed the rows to clover once again so the ground is never bare. The chickens get the benefit of all that freshly sown clover for fall fattening and going into winter. When the snow is not on, they will glean from that clover all winter long.
We leave those same rows and paths for two years, only tilling the rows for new planting the following year and then, every third year, we till up the whole garden once again, make new rows and paths and start the whole process all over again.
