1. Go to the bus stop. It's either a shelter-type thing on the side of the road or a yellow pole jammed into the sidewalk.
2. Look at the bus schedule. This is one of two things: a piece of paper with the bus routes and their arrival times, or a digital billboard that tells you what buses are coming and when they are due to arrive. Do you see them? Good, now;
3. Ignore the bus schedule. It is worthless. You should have gone here to search for the bus you needed to take and the time that you were actually supposed to be at the bus stop.
4. Stand around like an idiot for half an hour and wonder why the bus schedule is lying to you (mainly to toy with your emotions).
5. After around 45 minutes, look to the horizon. There should be a small, yellow dot in the distance. That's the bus.
6. Stand on the edge of the sidewalk and hold out your hand. This gesture lets the bus driver know that you intend to board it. Observe proper out-hand-holding etiquette: Your arm must be at a 90ยบ angle to the ground, palm facing down, with one finger outstretched, as if pointing to something on the other side of the street. The rest of your body needs to be facing the direction the bus is coming from. Don't stare at it directly; instead, bow your head in reverence. A tear of humility won't hurt.
7. Keep your hand up and your head down until the bus comes to a complete stop in front of you. If you did not follow step 6 to the letter, or if you waited too long to initiate it (the bus must be at least 5 km from the bus stop), then you will have offended the rumbling transportation god. You are now cursed and without public transportation. Go back home and try again.
8. If (and that's a big If) the bus stops and deems you worthy, the door will open. Step inside and thank the bus driver profusely for such a high honor.
9. Pay the fare. Coins only. If you don't have exact change, round up to the nearest Euro and pay that instead. If you're lucky, you will get a slip of paper that you can redeem later for a refund of the excess that you paid. If you don't get this slip of paper, it's because you have sinned and the bus driver, priest of the moving double-decker temple, has passed judgment on you. Accept his reprimands with nods and apologies. (Note: you will probably get yelled at no matter what you do. You probably deserve it, for the nature of the bus passenger is to sin. Accept your wretched fate gracefully and move on).
10. Find a seat and sit down. Congratulations! You have officially taken the bus in Dublin. That wasn't so hard, right?