Hiya OP! IME, this approach can be dangerous to embark upon for those without practice in dealing with spirits. It isn’t “Solomonic BS”; shamans have been making arrangements with their spirits since the dawn of culture. Not all consciousnesses are human-compatible, so the concepts of friendship and family can be absent from even the foundations of some beings’ programming.
Trade, however, is something more universally understood than compassion. Energy exchanges occur all the time between spirits, whether as part of a symbiotic relationship, a deal or arrangement, or a parasitic connection. The most essential aspect of trade is the exchange of value- something with strong natural virtues or deep resonance with a person has more market weight than a slapped-together payment.
Coercing beings into deals does motivate them to monkey’s paw it, but, approaching the situation as an exchange of events/goods and services between a merchant and a buyer leaves less room for variability in result. When a mutually beneficial relationship is established through energetic exchange, it motivates both parties to want to keep the arrangement in place- whether the terms of it are added upon or the nature of the relationship changes is dependent on the beings involved! 
In other words, don’t be an anime character, searching to increase strength through the power of friendship. That comes “second”. The first step is to establish a reliable connection and mutually understanding relationship by consistently exchanging energies, whether in the form of objects, events, or actions!