Elegant method of punching a hole through a wall to run cables?
There is a quick and easy way to do this, no special tools, $10 of parts, 20 minutes work if all goes well.  

Cut in an old work low voltage mounting bracket on either side of the wall, back to back 



and use a "duckbill" cover for a finished appearance, (the one in the photo is an Arlington CE1)



All you need to do this is 


a level to make sure you position the bracket straight / square,  
a pencil to mark the outline of the bracket, 
a drywall saw to cut a hole for the bracket,  
a screwdriver to screw the bracket in, and screw the duckbill on,
and optionally a studfinder to make sure you pick a clear hollow spot.  


When you pick your spot, try to match the height of any nearby electrical receptacles.  Try to stay well away from studs.  You can use a studfinder, or look for the nails holding the base molding to the wall - those will be nailed into the studs.  You can also turn off the breaker for a receptacle and take the cover plate off, you'll probably see the box is nailed to a stud, and you can go on the other side of that stud.   

When you cut the hole for the bracket, make a horizontal cut first so you can adjust if you miscalculate and hit a stud.  Don't plunge the saw in - take your time, use just a couple inches of the blade, just in case there's something behind there you don't want to hit.  

edit After you cut in the first bracket, move any insulation and poke the drywall saw through to the other side, just enough to pierce the drywall so you can place the bracket on the other side of the wall. 

If you stop using the pass-through some time in the future, you can just remove the duckbills and put blank covers on.