:) not since they stopped having the kiosks at the malls where you could do that, or dip your own candles for them to carve...

I remember them making 'seagull' forms (chevrons) by poking a chopstick through several layers of sand, but that and using a folded index card or a picinic-type ketchup bottle (some with the squirt tops cut off short) to help place the sand more accurately is about all I remember.

if you're planning on putting a live plant in there (one that's not a succulent, and needs dirt instead of sand) you might be better off putting a little pot in the jar, and layering the sand 'around' it instead of trying to make the hole afterwards.