Keeping things loose
Since concept art usually exists in a pre-production environment on a project, its main purpose is often to inspire the rest of the creative team you're working with. Some of my favorite moments of professional work so far come from being part of the pre-production phase known as the "Blue Sky" phase. The Blue Sky phase is all about ideation, and daydreaming about "how cool would this be" when creating the first batch of art. This allows producers, executives, and other artists to become inspired by possibilities before making design decisions on what to keep or what to remove in the context of designs, mood, and "feel" that the art provides.
When I worked for adidas on their X9000 shoe commercial campaign in 2019, we had some Blue Sky sessions to create some inspiring cyberpunk art using location scouting images pre-approved by the advertising campaign's executive team (Figure 11.17):