Well, I've started on this for a while. It's not much of an "essence" collection, but more of a mojo jar. A friend taught me this, so credits for out to him, and I'm just explaining.
It's a collection of random and miscellaneous items or just... things in a jar, container, whatever you want it in. Things that can store your energy into it, little bits and pieces that you feel is significant.
So far I've got incense ash, candle wax that I've used for a divination session. Keep adding more and more to it, and that can be like essence. But just your's.
If you wanted the aid of a spirit, then ask for its help. And not just stealing energy that wasn't yours in the first place and use it.