My general advice is don't be one of those dickheads that gets to security and only removes about 1/5th of the metal /. liquids things from their pockets and has to keep going round and round and takes ages to sort out their shite at security. jeez its not difficult and their are enough signs up telling you what to do.
So many factors affect timing
- size of airport
- queues at security and bag drop vary and can build up / chnage through the day
- hand luggage only is much quicker, only one queue
- some airline don't let you bag drop earlier than a set time anyway
- are you relaxed or a faffer
- do you want to eat once thru security before you board
etc etc personal choice.
Useful advice, if you are in queue and genuinely getting very tight - tell someone from the airline /airport staff and they will bump you through.