At least 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 in the lottery, a ticket worth an estimated $1.

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

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.