Minecraft wiki entry for Time-saving_tips, associated text: Once the player has obtained all the desired dye colors, and tamed all the wolves you want (tip: just tame two wolves and breed them infinitely), bones and bone meal have just two remaining uses: crafting bone blocks and rapidly growing plants. By all means, keep back a few spare bones in case you need them, but you should try to use the remainder. Sown on bare grass blocks, bone meal produces long grass from which you can collect a few seeds to start a wheat farm. About 6–8 doses of bone meal can convert a single block of planted wheat seed into enough wheat for a loaf of bread – useful for emergency food.
The player can also use bone meal to convert a brown and a red mushroom into two giant mushrooms, and by harvesting these you can easily gain a dozen meals' worth of mushroom stew. Even after its effectiveness was reduced (by about 50–70%) in the 1.5 update, bone meal still quickly grows trees, pumpkins, melons, carrots and potato plants to full size. Don't waste time waiting for your first few plants to grow; dose them with bone meal, and then you can start harvesting much more quickly.