The Powerball jackpot increased again after it remained unclaimed, but one lucky person won a couple million on Christmas.

One Mega Millions player has plenty of dough to ring in the New Year after drawing the winning number. After three months without anyone winning the top prize, a ticket worth an estimated $1.22 billion was sold for the drawing Friday night.

Just won millions in the lottery? Congratulations! Here's what to do — and more importantly, not to do — to avoid making some very big mistakes.