It's a beautiful solution. The sun is shining. The birds are singing. The flowers are blooming.
Then it happens. A third party intervenes, and shares their opinion on the design. They don't like the colors. They don't like the wording. They hate that picture. "Why does it fold that way?"
The client who works with the designer, listens to the third party, and considers their "suggestions."
They ask the designer to make the necessary "changes." The designer is confused, because, up to this point, the client loved the solution, and now it needs radical adjustments. The designer is also in a quandary because they know they have to charge the client for these changes. They inform the client, and the client is upset. "If you did this correctly in the beginning, we wouldn't be in this mess! Why do I have to pay for it?!"
The designer has a choice: acquiesce or insist. The designer wants to insists, but doesn't have a leg to stand on. The designer wasn't really clear about the parameters of changes that would require a fee, and what constituted necessary fees. So they have to acquiesce and work on the changes.
After many revisions later — and no compensation — the design finally gets done. But now the design is ugly, nonsensical, and the client is less than impressed. Everyone is glad it's done. But no kudos to the designer. In fact, the client figures they don't ever want to work with that designer ever again.
What went wrong? Was it the client's fault, the designer's fault, or the third party? I would squarely put the onus on the designer.
"Hey, that's not fair!" most designers would say. But it is just a fact. When a client comes to a designer, the designer cannot assume that the client knows how design works. (Otherwise, why are they coming to designers for help.) The designer must elucidate and educate the client, not only about the work involved, fees, and costs, but also how that particular designer works.
A good approach is for a designer to use a contract. The contract would stipulate who is responsible for what. What is to be expected — financially and otherwise. And the contract would allow for contingencies when there is a disagreement. This is important, because it is best not to assume anything.
Another approach is for the designer to provide a design brief when the client doesn't have one. It is a short document laying out the parameters of the project, how both parties (client and designer) plan to implement their working relationship, what constitutes a successful solution, and project timelines. In the above scenario, the third party situation can be avoided by stipulating that all parties be involved from the beginning. And if an unknown party does become involved, necessary fees apply.
Whether the designer uses a contract, design brief, or both, each party must sign and approve them to have a clear working relationship.
What about friends, family, or even pro-bono work? In my opinion, it is even more critical to have clear stipulations in these situations, because assumptions are more likely to derail not only the design process, but the relationships.