Today's pro tip is an oldie but a goodie (ha!).
A few days ago I made reference to a fairly well known trick that you just can't do in the arcade: how to get all the 1ups you want in the original Super Mario Bros. But, the game came out in 1985, which means that if you're younger than 23, this game came out before you were born. Add to that the Wii's Virtual Console service which lets you download and play these relics (*cough*), we've got a lot of new gamers who probably haven't wasted their childhoods spent lots of quality time practicing this game and might not know about it.
Okay, first make your way to 3-1. Specifically, the end where you see some koopas coming down the staircase. You'll need to make sure that you're either Super or Fiery.
Get rid of the first koopa, he just gets in the way.
Then try to time it so that you hit the second one so that it's just about halfway down the step above you.
Done right, and you'll know when you've done it right, you'll just keep bouncing off the shell, and eventually start racking up 1ups.
You can keep on going on for as long as you want this way, and your lives remaining display will get a little wonky.
A word of caution, though. If you manage to get over 127 lives and then lose one, it's game over. It's a glitch, so there's really not much you can do about that.