I did an exhibition of my art. It was nerve wrecking. I guess I forgot. This situation was particularly bad since I was using banana leaves which although hearty, can not be left in the afternoon sun for hours. I ended up doing some of the work in the morning but really the bulk of it happened in mid afternoon. At which point, I had to scramble to make sure everything was done. It worked out fine but the tight time schedule leaves no time for running out to purchase a last minute item. I have learned that to prepare as much as you can in advance. Get all the materials, including extras in advance. Do numerous tests to assure that the piece will work the way you envision. A bit of reality is that the ground is never really flat. And it is very difficult to even it out. This holds true at the macro and micro levels. I used flour in my piece to create a large circle and no amount of sweeping would clear it. There were always smaller and smaller bits of leaves, grass, debris which would be visible under the flour. I had to at some point "kiss it up to god" meaning that I had to just do what I could and then accept all the flaws. This type of work is not for the perfectionist.