Cut paper snow is one of my personal favorites. So much better than the shredded plastic stuff, it drifts and swirls through the air. Kind of off season right now, however. Colored paper might be fun, sort of like a confetti
cannon without the compressed gas. Regardless of color,
build yourself a sort of wire-mesh bingo ball cage and you can sweep up and "clean" the paper for re-use. Just make sure to do a good
hand sort for bigger items, I once saw a 3"
lag bolt make it back into the snowbag, then out of the bag during a rehearsal.
For just random effects, an opera I worked on did an
iris effect using a black
traveler hung close to a
guillotine black, and operated at the same speed. The singer was in front of this, and it would open behind her on a section of
stage with side lit snow, and backed by another full
stage black. I love that it's an
effect that technology would have permitted any time in the last couple hundred years. Would also look really cool irising open and closed on full sets for scene changes.
Putting a black
scrim in front of your
cyc creates great effects, especially if you
play with lighting the front of the
scrim vs. lighting the
cyc.
Speaking of scrims, my ex did a set for a show about mental health. Entire show was behind a black
scrim, with a box set that didn't reach the legs, and another black
scrim in front of the
cyc, but behind the set. As the audience tracked the movement on
stage, the scrims would create a shifting moire
pattern, and make everyone feel sort of off. Tons of non-specific complaints to the
box office, he considered it job well done