Theoretically, it would appear that one key to working with desires is to understand what Epicurus meant by "natural" and "unnatural". If I'm not mistaken, the unnatural desires are the only ones that he says have no limits.
Speculating on how these limits might work, what I come up with is that:
- Natural desires are limited through the natural limits of pleasure and pain.
- Natural but unnecessary desires don't cause any pain. They may be vain, but it doesn't really matter since there's no pain involved.
- Unnatural desires are not subject to the natural limits of pleasure and pain. This is due to being unaware of or consciously ignoring the experience of one's pain caused by a specific desire.