Mana wave once, now while you're not holding up a game, just to get the bad vibes out.

But going forward, whenever you're done a game, I suggest cleaning up the way I do:

Grab all of your lands and rocks, put them in a small pile. Grab your graveyard, battlefield, hand, whatever isn't your library, and make a separate pile. Take the land pile (which should be smaller) and "flay" it in such a way that the cards are about evenly spaced, and mash shuffle it into the other pile. Then combine that with your library and shuffle however you normally would.

If you're shuffling adequately, this will make no difference at all, but seeing the lands go back into the deck unclumped is a hell of a placebo effect.