The bones you gather should be sacrificed to the Chaos Altar, but it isn't a good idea that is why you shouldn't collect anything else than the bones you want to OSRS Gold sacrifice. This area is one of The most Player Active zones on Runescape It's located in the 38th floor of Wilderness.
This means that players of much higher levels may strike at you. It's best to keep them in the banks and run the Altar exercise after you have enough of the bones stored, but it's up to you to decide whether you'd like to put yourself at risk by using the equipment.
The second option for learning is via the Slayer. When you complete your Slayer tasks, you will find a large number of and ensouled Monster Heads, which can be revived by the Dark Altar. The killing of reanimated monsters can earn large chunks of Prayer experience, however, it's not a frequent method of farming, so don't ensure that you'll get enough Ensouled Heads in order to move the level from 1 to 99.
The process of runningecrafting requires a huge amount of Pure Essence for leveling purposes This is obtainable through mining and monster drop. The first method is easy but isn't very efficient, because you'd spent many hours digging rocks that provide no mining experience.
This is the reason why you should to focus on destroying Monster and other monsters, as they not only gives Essence in huge quantities, but additionally other valuable items can be useful to you. Most valuable are Gargoyles or Skeletal Wyverns that are on Buy RS Gold Slayer tasks. High-level players can also farm Zulrah boss to get drops at the end of the game as well as large quantities in Pure Essence.