ABC News' Yunji De Nies and Suzan Clarke report:

Mega Millions fever is gripping the nation.

The jackpot for the lottery game that's played in 42 states as well as the District of Columbia and the U.S. Virgin Islands is an estimated $363 million. Lives will change if a winning number is drawn Tuesday night -- or excitement will be stoked to fever-pitch if no winner is drawn and the jackpot increases.

The prize is the third-largest in the game's history. The largest Mega Millions jackpot ever won was $390 million in March 2007, according to Mega Millions.

So do you have a strategy for purchasing the golden ticket?

While the chances of winning Mega Million are slim - the odds of winning the game's top prize are about 1 in 176 million -- that hasn't stopped many millions of people from dreaming big.

Richard Lustig is a seven-time lottery winner in Florida who plays the lottery every single day, like a full-time job. Sure, he loses sometimes. But he's also won more than $1 million.

"I keep on winning because I follow my method," Lustig told "Good Morning America."

Here are his tips for buying tickets:

Pick your own numbers. Don't leave it up to the machine. Lustig advises against playing Quick Picks, the phrase describing the number the computer picks for you when you don't use your own. Do your homework. Go online and make sure the set or sets of numbers you play have never come up before. Stick with your strategy. You have to learn what number to play and how often to play. Commit to your numbers and stick to your strategy. Avoid lottery fever. When jackpots get this high, Lustig says, people tend to get lottery fever and spend a lot more than they normally would or can afford. Don't go crazy; the odds are still the same no matter how much you spend.

Cynthia Stafford is another everyday person who earned the title "lottery expert" the best way possible, by winning the jackpot herself. Five years ago Stafford was struggling to pay bills while raising her late brother's five children. She bought a $2 lotto ticket that made her the sole winner of a drawing worth $112 million.

Stafford won her jackpot by playing Quick Picks, breaking Lustig's number one rule.

"All I chose was the amount I was going to win," Stafford said on "GMA," alongside Lustig. "I did a little meditation and 112 came to me and I said, 'Okay, that's what I'm going to go for.'"

Stafford took a $67 million lump-sum payout from the lottery and, after paying her bills, helping her family and donating to charity, used the prize money to form her own production company, Queen Nefertari Productions.

She, like Lustig, continues to play the lotto, though not as frequently.

"I may play once or twice a month," Stafford said. "Just a dollar or two because I won with a $2 ticket."

Mathematicians and lottery officials have said that the odds of winning are always the same regardless of how many people play because the lottery is always drawn from the same set of numbers.

They agree that allowing the computer to choose your numbers does not necessarily increase your chances of winning.

Statistically, playing the same number time after time doesn't help you win any faster either.

But you have to be in it to win it, right? If you've plunked down your $1 for a ticket, the stars somehow align and you hit the jackpot, don't start spending it right away. Experts say to get professional advice before you begin to enjoy your winnings.

And expect to pay a pretty penny in taxes.



