|Q: Where do you get bone materials?|
A: First I started with cow bone. You can collect the remains of bones from the kitchen or buy bone in a market (a whole cow leg, eg). For carving you should take tubular bone from animal extremities, any other kind of bone are porous and not suitable for carving. You can also pick bones everywhere around, gnawed by dogs and washed by rain.
Before carving bone should be mechanically cleaned from soft organic remains and grease. For degreasing bone should be digest in a solution of baking soda: one pack of soda by a liter of water. Boil it for a couple of hours changing the water periodically. When you get dirty foam cap, consisting of organics and grease associated with soda, the solution should be changed, continuing to boil until foam is clean and white.
It is also desirable to have clay on hand, for a preliminary modeling of what you want to carve. When comfortable with the unpretentious cow bone, you can go to capricious "noble" materials: mammoth tusk, walrus tusk, cachalot tooth, ram's horn. These materials are more dense, and each has its own mood and peculiarities. I think when you get to the processing of tusks, my advices are no longer needed.
Q: Where do you get mammoth/walrus tusks and sperm whale teeth?
A: Mammoth tusks are widely excavated from deep-frozen soil in Siberia, Alaska and some other cold or polar regions. Here in the Far East (I live in Vladivostok) such materials are not rare for those who are looking for them.
Mammoth tusks are widely trafficked (mainly not legal), the resources are rich despite the trade volume of thousand of tons digged out every year. there lived really many mastodons and mammuts!
I buy the materials from traders, mariners often bring them from north trips as souvenirs or for some crafts, usually walrus and cachalot bones are used for knife handles making.
If you live in USA or Canada you can obtain bone materials from Peter Evans
Q: What tools do you use?
Sorry, these articles are not translated to english, I don't have enough time (but I plan to do it some day).