I think you need to decide if you want "deep litter" or "deep bedding". In my limited experience, pine shavings will give a wonderful deep bedding but will not give you a true deep litter. I took everything out of my coop and run at the end of the first year. I was amazed, and a bit dismayed, to see that after a full year, even with adding other material to the litter, the pine shavings were still pretty much intact, even in the lower layers that were resting directly on the ground. They had broken down some around the waterer and around the edges of the run where rain and snow melt moistened it, but other than that after a year I had, well, pine shavings. Not true deep litter, but deep bedding. Nothing wrong with that - the girls loved it and did very well on it, but deep litter it ain't!
I changed things up, following the advice of folks who have been doing this far longer than I have. @Beekissed has a really great handle on this deep litter stuff. So now I use lawn and garden waste, weeds, dried leaves complete with any little twigs that are in there, whatever I have on hand. If it's too dry, I give it a light mist, flip it, and add a little more green stuff. If it gets to damp, especially in those areas I mentioned before, I drag some of the damp into the drier areas and pull some of the dry over the damp areas, then give it a flip. I am very happy with the way everything is breaking down now.
Right now, with sub zero temps, I am finding that the litter isn't working as well, so more carbon based materials are going in. I'm still learning as I go, but when I showed Bee the great earthy litter that was down in the lower layers she said that was just how I wanted it to look. So I'm closer now to true deep litter than I was before.