People say that pyramiding has to do with overfeeding, but I think that's nonsense. Wild tortoises walk around grazing everyday. Then again, I'm not into limiting food intake with my reptiles unless completely necessary (like my beardie who used to eat tons of crickets and no greens).
I would say pyramiding is just something that comes of inappropriate husbandry. I try to offer good heat and humidity gradients. Humidity plays more of a role in pyramiding than many people think. I noticed over the years that most tortoises (particularly redfoots) that are kept in environments with an overall low humidity (kept on dry substrate) end up with bad pyramiding, whereas those that are kept in an overall more humid environment tend to have well-formed shells. In general, contrary to generally accepted tortoise theory, of the redfoots I've seen locally (well, most tortoises in general), the only ones that had pyramiding were those kept in an open top enclosure. I saw one beautiful redfoot that was kept in an enclosure with only a couple of small vents, kept on what looked like a moist combinatino of cypress mulch and dirt. Then, conversly, I saw some redfoots kept in open-top pens indoors on cypress that had the worst pyramiding I've ever seen first-hand.
I know this goes against what most people commonly accept as general captive care of tortoises, but then again, if we don't look around and think outside the box, we'll never get anywhere close to better husbandry.
So that's my $.02. Higher humidity, and make sure there are good temperature gradients. Another local that keeps redfoots in enclosed terraria with high humidity once told me that if you keep redfooted tortoises, you should keep them just like you would an iguana, except terrestrial. To me this means humid environment. A breeder he works with keeps his cages so humid that there is condensation on the glass.
This is just some food for thought.