And the list is likely to be different for all travellers.
For security screening I am not going to get ready before hand. Laptop bag comes off shoulder, unzip bag take laptop out and put in tray, wallet and phone(s) go in laptop bag, take jacket off and put in tray. There is nothing else on my person other than boarding pass. It has taken a total of <1 minute. I generally stay at the back of the bench and if there are people already in front of me I have not held anyone up. If I am the first in line I ask people to go through while I get ready. I hate it when people go past me or I have asked to come through then do the same as me and make me wait.
People who have no consideration for others around them including talking loudly, using mobile phones and talking loud enough so others can hear. Seriously why do people wait until they are in enclosed spaces (lounges, trains, buses) to conduct their phone calls? Do it in your own time and when you are alone and let others have their peace.
People who recline.
People who hog armrests.
People who take forever at premium check-in.
People who use knife and forks to eat the meal in economy, even pasta, and then also use a knife to meticulously cut the bread roll with knife and spread the margarine. Seriously? A fork is more than enough to do all those tasks.
People who expect you to give up your pre-allocated seat so they can sit together. Get yourself organised like I have otherwise just put up with your allocated seat.