There are a bunch of code snippets that I always forget. In an attempt to organize my life, I'm going to throw them up here. Hopefully Matt will too.

Removing all Children From a DisplayList

 
while( numChildren > 0 )
{
	removeChildAt( 0 );
}

Make Sure Everything is on the Whole Pixel

This is just a useful concept to throw out there, since everything should be on the whole pixel if you'd like it to look crisp.

 
override public function set x( value:Number ):void
{
	super.x = Math.round( value );
}

Pretty easy huh? Just do the same for width/height and y.