Here are The Traveling Professor's tips for elite flyers:

Upgrades:  Based upon availability, coveted first and business class upgrades may be given free to elite members and their traveling companions  regardless of the elite status of the companion.  In fact, I am writing this now after me (and my companion) were upgraded from coach to first class.   However,  book the ticket through the elite status account for both travelers through the traveler with the highest elite status.  For example, I have a higher elite status (Platinum) than my traveling companion (Gold) on American Airlines.   If we booked tickets separately, I have preferential upgrade status (as well as all other Platinum flyers) to any Gold members.   But if we booked both tickets on my account, it is like we both have Platinum status. 

Elite Status Match:  Have Platinum status on American but no elite status on Delta?  Apply for a status match with Delta.  Prove to Delta you are a Platinum member and Delta may automatically grant you equivalent status for a period of time while you prove you can be a frequent flyer on their airline.

Mileage Runs Can Be Worth It:  Let’s say it is coming close to the end of the year and you need 2,400 miles to reach Platinum status.  It might be worth it to buy that dirt cheap single-day turnaround ticket to New Orleans to put you over the top for another year of Platinum.  My travel partner did this last year and there were at least 6 other flyers on her flight doing the same thing.

Join the Club:   I would say if you take over 10 flights a year, join an airline lounge.   Costs can be $350 or more per year but there is nothing like relaxing in a lounge waiting for a flight, especially if there is a delay.  Some credit cards give free lounge access.

Credit Cards:   Some credit cards, the MasterCard Executive World Traveler comes to mind, offers free Admiral’s Club lounge access, waived baggage fees, discounts, and boarding priority.  It’s almost like having elite status.

Make Changes at the Lounge:  If you belong to an airline lounge, it is usually best to make special requests (upgrades, earlier flights) at the less crowded lounge as opposed to the ticket counter.