The 12 Sex Positions of Christmas: Come Down the Chimney

Without the heavy packages.
 
                         
 
 
 
Technique: On a flat surface like a countertop (ahem, the chimney), have the woman sit on the man's lap as he penetrates her from behind. To ease the position, have the man guide the woman up and down by holding her hips. For a deeper penetration, the woman should lean forward.
Difficulty: 2 out of 5. Straddling the "chimney" takes some balance, but it's not like you're traveling around the world in one evening to bring joy to the entire population of small children or anything.
It's Great For: An intimate, lazier spin on doggy style.