Well, I've used actual sandpaper for that effect--like sand on the beach for a card?
Another thing I've tried, is just painting on some Crystal Effects where I want it, and then dipping the card stock into a dish of sand/spooning it on where the CE is.
You can get pretty candlescaping sand at shoppes like Pier 1 Imports--very nice stuff. I suppose it's kinda messy (the process), but it looks way cool when done!
OH Oh!!!! AAAAAAAANNNNNNNND, If you want, try using SU!'s HEAT N' STICK embossing powder!!!!!! You can rub the versamark pad directly to the paper where you want it OR EVEN STAMP AN IMAGE (!!! WOO HOO!), emboss with the HnS EP, THEN dip into sand, as well!!!! Re-heat to set it--basically, it's the same effect you'd get if you spooned glitter over it, etc., you see? Also very cool!!!
Dang, sorry. Got a bit carried away. . . :o
HTH,