When I was a child I just loved to draw and paint but, as I remember, before I even could begin to draw accurately I used to color in. The next stage was to learn to draw using stencils and then I graduated to be able to draw freehand which provided me with an absolutely fantastic sense of achievement. I went on to love drawing but the point I am trying to make is that it all started with the simple yet effective art of coloring in!
You can metaphorically take a page out of a coloring book, and break up the work into a few sections. Each team member or group within the team should first be instructed on which part of the page they are going to color, let them know what color they can use, and when their turn will come up. Next, after each team member has finished their part of the coloring than take the completed picture and hangs it up so that every one can see their part of the picture and the entire teams contribution.
The repetitive, low-stress, and "no brainer" act of color lends itself to relaxation. The calming effects not only helps to reduce stress levels, but also can help to bring you back to your youth. The awesome part is that anyone can do it will no skill set required! Grab a crayon and you are good to go. You can make it even more enjoyable and have your kids or grandkids color with you. Depending on the age of the young ones they may be interested in the adult coloring books, others still wanting to color a cow, astronaut, or pretty flower arrangement.