I use this art project with my students at the residential therapeutic program I work at.
All you need is:
Masking or painters tape
And some way of putting color on the paper. Paint and brush, crayons, etc. Just as long as you have many colors to work with.
Step 1: Place Masking Tape
Free your mind of preconceived notions of masking tape direction and uniformity.
Step 2: Create Geometric Shapes
Don't form the shapes consciously. Let the shapes form your conscious.
Step 3: Color
You can go with a color scheme or pick them at random. You can repeat colors or use new colors for each shape.
It does not matter. All that is important is that you color carefully, take your time, and let the coloring bring you into s more Zen state.
Step 4: Remove the Tape
Step 5: Admire
If your really want to practice your Zen, tear up the paper and throw it away. To significance of life's impermanence.
After all it is not the destination but the journey that is important. "'Cause how you get there is the worthier part."
Step 6: In All Seriousness
I myself have been trying to lead a more Zen lifestyle and arts and crafts and DIY have been a big part of that.