I'm going to fly from Düsseldorf (Germany) to Newark with Lufthansa. I've checked in online, but want to check in baggage at the airport. When should I be at Düsseldorf airport?
For most international flights at European airports, it is 2 hours, although if you look at the actual print of the eTicket, it will say 90 minutes. Dusseldorf airport recommends 90mins to 120mins but says to confirm with the airline.
My strategy is to aim to be in the check-in line by 90 minutes before the flight and I have never missed a plane. Most of the time, with the rest of the paperwork ready, I even have time to wait for boarding. In very rare and extreme circumstances, I felt the need to rush to the gate.
This means that plan for time to get to the airport according to typical traffic for that time, plus a small leeway, plus time find your way across the terminal and to the right check-in counter.