When you leave your stroller at the gate, make sure that you have folded it and that it will stay folded. If there are any removeable pieces that might either come off or get damaged during travel, remove those and bring them on the plane with you.
And, the last thing sounds obvious, but it apparently is something people forget....
remember to pick up your stroller when you leave. My youngest DD uses a wheelchair, which means we usually are the last (or almost last) to leave the plane. We often see strollers still sitting at the gate when we leave because people didn't think of it in the rush to get out.