General Method Description

Jennica's ring is a reward for the completion of the quest Spirit of Summer; when activated near an appropriate Wilderness portal, it transports the wearer to a part of the Spirit Realm, a mystical "inverse" of RuneScape. One of these portals is located just south of the Axe Hut in the deep Wilderness, and when you go through the portal you find that the axe hut is filled with level 42 ghostly warriors. These monsters are easy to kill and have excellent drops, especially mind, cosmic and chaos runes, making them great for both training and earning money. The only real danger with them is getting to them (since they are in the Wilderness), but you don't have to travel far in the Wild, so that risk can be managed.

Dharoks is the preferred method of fighting here; even though Dharok's axe is a slow weapon, you get a lot of one-hit kills which speeds things up nicely. These monsters hit so little, though, that I recommend taking with nitroglycerin (or "unidentified liquid") to reduce your hitpoints total down to a level where Dharoks works well.

Note that there is no real use for any particular familiar here, so just use a foraging familiar to earn more money.