I know it sounds obvious, but don’t trust the booking agent, or the online website for that matter, to give you the best seats available. Take, for instance, my upcoming trip to Prague for E-ATP. I am flying on Delta Airlines and my seat for the leg from CDG to BOS was listed as “Requested.” What this means is that since the flight is operated by a partner airline (in this case, Air France), Delta has to request the seats and await a confirmation from the partner. It’s been almost two months since I booked the tickets, so I found it odd that they were still listed as requested. I called the airline and they told me they had requested <insert lousy seat here> as my seat and were still awaiting confirmation. A quick look at the seat map showed me that there were 3 seats together (I am traveling with 2 companions) in a row with no seats in front of it–providing necessary legroom on a transcon flight. I asked the agent to move all 3 of us there, which she happily did. Interestingly enough once we were moved, the seats were automatically confirmed by the partner airline and were no longer listed as “Requested.” Score +1.
The moral of this story is don’t trust the booking agent to give you the best seats, or actually seats at all in some cases. And, check on your reservations from time-to-time between booking and take-off to see if better seats become available as people cancel or seats that used to be upgrades are released for general consumption.