Use a hyphen to form compound modifiers. They belong together. They are not part of a series that can separately describe the noun. I think Steve is a well-intentioned volunteer. Steve is a helpful, supportive volunteer.
Most people think they have a well-developed sense of style.
Steve has a highly developed sense of style. Susan has an open-minded view of the world. Doug thinks he has very liberal views. I think his proposal is short-sighted. But be careful to distinguish between a compound modifier and the same words not used as a modifier.