I'm down for graphics making. Been meaning to use photoshop, since I'm subscribed
I'm a little tired to come up with ideas right now, but if you nail down what emotions you're representing, I'll pick a couple and art the heck out of 'em or whatever.

Ok, finally remade my list of the colors and associated emotions/traits.

Red: Strength
Orange: Endurance or Creativity
Yellow: Intelligence or Understanding
Green: Healing
Blue: Serenity or tranquility
Purple: Transformation or Wisdom

Again, these will all be fairly abstract concepts so the meaning can be put in to them by the person participating.

The above example symbols are along the lines of simplicity that I want, with basic shapes and lines, and nothing overly complicated. For instance, the lower left one I can imagine being in green, perhaps with some leaves or bark effect, to give a nature look. The very  middle one could be a blue for water as a serene calm symbol.

That's the basics of my thoughts.

While this is mainly a subjective project, if you're going for simple and meditative, I'd recommend against glow effects and gradients. They look cool, but tend to get cluttered real quick.

I've uploaded Intelligence and Serenity into the same folder as the above link, Fireproof. Lemme know whatcha think.
Also, I put intelligence on a black BG because it was burning my retinas. I can do whatever BG changes you'd like on any of them, though.

Flat coloration is the right call, I think.

What do you think of the shade? It might be too vibrant, but that's me.