Well, your first option is to pray.
But your second option: look.
No, seriously. Look for stores. Gamestops / EB Games are no-goes, there's literally a 0% chance they'll have it before street date. Walmarts, KMarts, Targets, etc tend to have games early, so if you want to try and bargain for Smash 4 early then go to one of those stores. If not, well I have heard cases of people pre-ordering games from online stores and getting them early (as is the case with some products, namely Pokemon TCG stuff).
Just try and find a store who's main priority ISN'T games, and you can more than likely pick up a copy. If their main priority is selling games, then...well, try and get lucky. Big chains, as I said, don't put up before release date.
Good luck. I know I'll be searching too.