If your talking about snow laden branches or snow covered rocks, hand embrodiery is nice, I know labor intensive but nice. Or use a straight stitch going back and foruth on chosen area. If you want snow falling how about little white seed beads? Or the clear sequins, spread about? I know some of this requires hand work, but the effects are sooo nice, and worth it, unless your wanting quanity instead of quality. Just a thought,,,,,