Interesting, but I'll probably never try it!
Christmas Cake...I dont think I could do this but its cool
Staples does oversized prints called "engineer prints." The largest size is 3' x 4' and they cost only $4.99!!
Dry erase markers work on most school desk tops (think I'd try it first - and I'd want a low-fume marker).
Fill balloons with water and add food coloring, once frozen cut the balloons off & they look like giant marbles. Line the walkway in winter...
This is just one of the amazing creative Christmas card ideas on this site.