My biggest hate on single aisle aircraft where airlines don't allocate seats is that pax fill seats from the front, rather than making their way down the cabin.
I'm always very polite when asking people to move down the cabin to choose their seats but quite often I get rolled eyes or a rude response. Said pax are also usually the 1st to complain if we depart late. I will always take extra care of pax who assist me with boarding & know the drill.
Helping people stow bags keeps the flow going too, even if it results in a bit of a sweaty boarding... but I could do with the exercise
