LPT: if you are worried/anxious that something you want to do might annoy other people, think about how you would feel if someone else did it. Chances are if you wouldn't care, neither will they.

For example: I was flying with a friend who refused to put his seat back because he didn't want to inconvenience the person behind him. I used to feel that way, too, until then one day I thought "wait, do I care if the person in front of me puts their seat back? Of course not, it's a part of flying and it barely changes my space." From then on, I have applied this method of thinking any time I am in a situation where I feel unsure/nervous of potential reactions.

Disclaimer: this does not work if you are a grumpy pants who hates everything