It was my son's birthday last week, and he got two wonderful Lego building sets. Of course, his first inclination was to rip open the boxes, dump the contents on the floor and start building — which was fine, except some of the parts are, like, 1 millimeter in diameter.
New process: the moment someone opens a Lego set, the bricks and instructions get dumped into a gallon-size Ziploc freezer bag which I label with the set's name and number. When it's time to play, all the Legos get poured into a cookie sheet. No more tiny parts underfoot or under-couch, and they're easy to dump back into the bag.
Related: Shovel up the Legos