Take your nose out of your screens and look around you, you heedless feckwits.
If the ticket machine has a note that says cash only, don't approach with your debit card and go "all pissy whiskers" when you can't top up your Oyster card.
Thanks for that phrase. 
Similarly, if it says no change given, it's talking to you too.
Don't stop or slow down at the top or bottom of escalators or else you'll get rear ended by a whole bunch of irate people who can get even more pissy whiskers than you.
Here in the West Midlands, where there is one door on the bus, by the driver, to get in and out of, let people off first and stop whining when you have to reverse out again to let someone else off.
FGS - this isn't London where the buses arrive every 5 -10 minutes. You've had plenty of time, waiting at the bus stop, to fish your bus pass out of that black hole you call a bag. You've got pockets even - can you not put change or pass in your pocket, like I do?
I don't care if Shanice is going to your Mum's or her boyfriend's tonight, how long it'll take you to get back for your warm coat before you come back into town again or whether you got another suspended sentence (actually, the last one, maybe) - just shut up.
I have my own headphones thanks, I don't need to hear yours tissing rhythmically away beside me as well.
It's a bus not a playground. Stop letting your kids hit the bell. Stop them running around and stop them batting balls, balloons and other toys up and down the aisles.
If it's such hard work, don't bother going upstairs with your kid, that's what the downstairs is for.
Stay off the bloody stairs.
Vaping is just as offensive to asthmatics as smoking. It's not just water vapour, you numpties.
Don't sit on the aisle seat, leaving the window seat free and then go all pissy whiskers when someone wants to sit down.
Seat swivelers. You're fat, I'm fat, stop being so hopeful. We are not going to get past each other without significant damage.
When you do get up, stop blocking the way off the bus. You're fat, I'm fat, we're not going to be able to pass each other in the aisle. It'll be like watching two balloons squeeze through a letterbox together. Don't be stupid.
Stand towards the back of the bus so I have a fighting chance of getting off and down the front of the bus before the doors close and the bus moves off.
You there! With your nose in a screen. That elderly lady with a walking stick needs a seat. Don't pretend you can't see her.