When one thinks of artists and creativity, what comes to my mind is a vision of the studio work table, art materials all around, whether its watercolors or stained glass or even melting glass rods at my torch for beads and in what initially is an orderly environment, without notice or intention becomes what some people would refer to as a mess. This "mess" which becomes the artist's palette so to speak, is what the creative process develops from in a way not predictable, has no relationship to what we know as the passage of time and allows the artist opportunity to unconsciously disassociate from the surroundings in order to indulge in the creative process. Hence, the explanation to any question of how can the artist creates for so many hours?!
The artist often has many limits imposed upon their creativity, some of them self-imposed due to restrictions of the materials used, the availability of a particular art material needed at that very moment and the conscious decision of that missing art material dictating whether or not for example, you use the glass rod of opaque copper green or instead go with the transparent mosaic blue that you have within reach of your fingertips. Even if you had the initial vision of the beads you would create that day at the torch, many times you will find the need to change the design or colors based on what art materials are readily available at that exact moment. Ah,... I know you're thinking that the artist is lacking in organizational skills; perhaps this is true to some extent. One must consider that at any given moment the creative process will take a turn that the artist never expected which hopefully, is a desired end result.