Have you seen the video 'Johnny T's NYC Tourist Tips'? It's very funny.

If you haven't, the takeaway is YOU = TOURIST = JERK. Every city has its own unwritten rules and quirks and governing principles of which tourists are blissfully ignorant. The bad news is that this can make tourists annoying, even jerkish. The good news is that at least some of this jerkishness could be mitigated by knowing a few, key nuggets of information... things that can make moving through the city easier and faster and with more awareness.

The kind of thing Johnny would tell you.

This is not an eating guide, a shopping guide or a museum guide. It's just a humble list of do's and don'ts written from the perspective of a local, about how to win at Paris.

VISITING STUFF

DO

Take lots of photos. Enjoy the moment. Do the silly tourist things. You are a tourist, and no matter how carefully you dressed this morning to try to blend in, you didn't. We can still spot you a mile away. Just go with it.
Be prepared to stand in line for up to a couple of hours for the major landmarks. Paris doesn't really have a low season, so every weekend of the year = queues. Judging other people based on their shoes will help to pass the time.
Haggle with the guys selling Eiffel tower statuettes. You can get them for about 20c each and they are a really lazy present for people back home. They are also exactly the same as the ones you will see sold for 40€ on the Champs-Elysées.
Be nice to aforementioned Eiffel Tower guys. Sure, they are a bit annoying but they are probably illegal immigrants working under very uncool conditions and at least they have something to offer. Which brings me to...

DON'T

Give money to anyone who approaches you with a sign, pretends to be mute or blind, wants to give you a gold ring, a string bracelet or have you sign a petition. They are part of a criminal pickpocket gang.
Put anything you want to keep in your back pocket.
Line up at the Pyramide at the Louvre. Take a 'secret' entrance way (Lions Gate, the métro) and skip the staggeringly enormous queue for just a large one.

DEALING WITH THE NATIVES

DO

Be nice. I know, Parisians are not known for their hospitality. A native stranger will rarely stop on the street to help you if you look lost, or chase after you with the glove that fell out of your bag. But everyone you encounter is battling to get around the same busy city that you are, except they don't get to leave on Wednesday. Be kind to them, get the hell out of the way and let them get on with their lives.
Try to use whatever French you have. Even if it's just Merci and Bonjour. Saying a loud 'Thank you' to the busy waiter who brought you your plat du jour makes everyone within your earshot cringe.

DON'T

Assume everyone speaks English. Or whatever brand of thickly accented English you speak.
Assume nobody speaks English. As David Sedaris so brilliantly put it "it's not as if English is some mysterious tribal dialect spoken only by anthropologists and a small population of cannibals". Paris is quite a multicultural city and you are as likely to be standing next to another tourist as a Parisian.

USING THE METRO AND RER SYSTEM

DO

Walk at the same pace as those around you. If it's rush hour, rush. If it's 9am on Sunday morning, you can afford to amble.
Keep your metro ticket handy until you are well and truly outside. You need it to get out of the RER system, and although you don't for the Métro, you never know when you might get stopped by an RATP guard. Pleading 'tourist' doesn't always fly.
Touch people lightly on their back and say "excusez-moi" when you want to get off a crowded carriage. A small touch helps get the attention of people who are listening to music or buried in their phones.
Be ready for your station. No-one will be impressed if you jump up from your window seat at Châtelet- Les Halles, trying to fight through a packed peak-hour carriage as people are already starting to board. Subtle signals like putting your bag on your lap, shifting in your seat and looking expectantly at the doors let your neighbours to know you want to leave.
Get on and off the carriage as quickly as possible. For the love of the old Gods and the new, do not stand directly in front of the door!
Be really careful when taking the RER C to Versailles. It's a famously confusing line, with many different and confusing termini.

DON'T

Stand on the left. Don't do it!! In the name of everything that is holy, never ever stand on the left. People who stand on he left on the escalator should be shot.
Pause at the top of the escalator when you get off. Chose a direction and start walking!
Stop abruptly in the middle of the corridor and pull your map out.
Put your enormous suitcase in front of the doors. Push it into any available corner and if possible, perch on top of it and look apologetic.
Totally trust the arrows and directions in the metro. A healthy level of suspicion will serve you well here. Always verify that you are still going in the right direction and keep a keen look out for tiny signs pointing you anew. You'll get lost anyway as the Parisian metro system can be incredibly confusing, but you might get loss slightly less.

USING THE VÉLIB SYSTEM AND RIDING IN PARIS

DO

Ride as if God invented bikes, and Paris, for your individual pleasure. You need to be confident in Paris to stay safe. Drivers are as homicidal as in any other major city, and if they can smell hesitation or fear on you, you're a goner.
Ride like you own the damn road. Defend your lane. Flip the bird to drivers who try to cut you off.
Always glance over your shoulder before you veer or turn. There is probably a silent ninja bike courier in your blind spot who is just about to overtake you.
Scream at a**holes who walk on the bike lane between Concorde and Pont Alexandre III. There is a pathway for them literally 10 meters away. They are all tourists so feel free to scream in any language.
Check your Vélib (rental bike) thoroughly before you take it out. Tyres? Two pedals? Chain? Brakes? Seat post that stays up? You would be astonished at the condition some Vélib's are left in, so approach every vélib as if it was last ridden by a 300kg stunt rider with a death wish.
Turn the seat to face backwards if you find a dud vélib. It's the secret code, and other riders will thank you for it.

DON'T

Break traffic rules. Unless you're really, really sure you'll be safe and it won't affect anyone. Which as you are a tourist, won't ever be the case. Follow the bike lanes where possible. Adhere to traffic lights.
Take the last empty Vélib deposit spot without checking that someone else isn't already waiting for it. You will definitely get cussed out.
Forget to put your Vélib back carefully, and wait for the green light and 'bip'. That large credit card deposit you made isn't safe until this is done.
Keep your Vélib for too long. After 30 minutes, it starts to get really expensive. After 24 hours, you bought it, son. This is a short and intense relationship. Let it burn hard and bright, then let it go.

So what is my final piece of advice? My hottest tip? My last parting words of wisdom?

It's simple really.

YOU = TOURIST = JERK.

Don't let it get you down.