First calculate the fees. Business travelers have always liked elite status for the free upgrades to business or first class. Leisure travelers, however, can now find benefit in getting for free things that the airlines regularly charge for - such as checked bags, exit row seats or changing your flight times. Benefits extend to spouses and kids on the flights with you, so savings can be substantial.
Check your balance online. Only travelers who already have at least 20,000 elite-qualifying miles on one airline for the year, or will, after you factor in travel already planned for later this year, should make the push to get to 25,000. EQMs are based on the fare you paid as well as miles flown. They're not the same as award miles.
Earn extra miles when you can. Airlines occasionally offer promotions for double elite-qualifying miles on select flights. Read your frequent flier newsletter to see what's going on. Some don't even require flying. Delta is offering one EQM per dollar spent, up to 10,000 miles, when you book a stay of at least two nights at a Hilton hotel before December 10.
Think about booking a run mile. This time of year, you'll see plenty of elite wannabes making flights going to say, Alaska and back without leaving the airport just to earn miles. While you don't have to go that far, you can check fare sales to see where you can go - cheaply - for a weekend getaway or two.