Could not possibly agree more, they are the worst. System would be massively more efficient and pleasant if everyone followed basic etiquette.
Other annoyances;
When you get to the bottom of the escalators don't just stop in the middle looking at phones and wondering what platform you need. Stand to the side.
Observe the queues next to each door position on the platform and join them. Do not just stand in the clear space in the middle. Following on from that, let people off the train first!!
Walk down the platform don't huddle at the entrance to it.
Don't wait for the gates to close before tapping your card. Just tap and check for green light.
I actually expected people to stand on the "left" of the scalators - just like how they drive on the left and overtake on the right - but they didn't.
They stood on the right.
Stand on the right on escalators, let people off of the carriages before you barge on, don't stop suddenly without checking who's about to walk into you, don't run into tube trains as the doors are closing only to get stuck and hold up the train, DON'T HOLD THE DOORS OPEN, go up and down stairs on the left, corridors etc, stay on the left and don't fuck around at the barriers. Have your card ready, your contactless ready, take your kids, cases, whatever through the wide gate. Don't play whatever shitty video you're watching to the whole train and certainly don't subject others to your music taste.
DO ask people for directions or for help, people may look tired, they may look grumpy they may even be those things, but most will be more than willing to help you.
EDIT: Others covered a few important ones I missed too; backpacks off, walking N-abreast so as to be blocking others from passing are a big no-no; you may be having a leisurely stroll, commuters have places to be, whether at work or at home with their families and their feet up after a long day.
Adding to this: Don't jump aboard wearing your dirty working jumpsuit smeared with paint, cement, oil. Also stop loudly arguing with your partner over phone. Get your shoes off the chairs.