functions and fractals - Koch's snowflake, Serpenski's triangle
anamorphic art (distorted grids and proportional reasoning)
sculptures based on the platonic solids
There is a neat book called for geometry and art (may even be cleverly
titled "geometry and art") and a little device out of plastic called an Eye
Cue for discovering the geometry in compositions -
spatial visualization - drawing one side of a still life of blocks and cubes
from an opposite side -
Quilt patterns - (I have an old article somewhere from Quilter's Newsletter
magazine on two women that patch fractal patterns) -
Golden Ratio - the relationship between A, B and C - wonderful for
nonobjective paintings
There has been so much on here for art and math, Bunki has some great stuff
to share on her website - as do others. You may want to see if NYUS has any
information - there is/was a math professor that used to run workshops for
artists and mathematicians to work together -