Ask nicelyYou won't know unless you ask, and that can also apply to scoring an upgrade. Some seasoned travelers have gotten upgraded during check-in at the airport or at their gate. There's no easy way to do this and no guarantee it'll work.
What are the best seats to book in economy?
Best seat for peace and quiet: A seat near the front. Best seat for legroom: A bulkhead or exit-row seat. Best seat for sleeping: A window seat in a bulkhead row. Best seat for extra space without a seatmate: A seat towards the back.