Tip 06: You need your ticket people
To get in or out of the tube network you need a ticket.
Whether it's an Oyster card or a retro paper ticket, you need one to get through the gates at the start and at the end of your journey.
It is really worth noting that (generally speaking) once at the top of your ascending escalator you will need to pass through a ticket gate pretty soon.
So get your ticket out before you get there. So many people seem to forget that there are gates on the way out. They stop, stunned like a rabbit caught in your headlights, frozen, not knowing what to do. Then they spend five minutes rummaging through their handbag / shopping bags / coat pockets looking for that magical token that will allow their escape.
Get it out on the way up the escalators, get it out while walking along the concourse, get it out before you get to the gates. At that point it's too late. You'll disrupt the flow and add the already high blood pressure of all those around you.
On a slight tangent, the same rule applies while queuing at cash machines and queuing at the till in a shop (especially supermarkets): you know you're going to need your money or you credit / debit card, so get it ready. You must be expecting it; you joined the queue!