Whether or not is a faded thing, it is a profession courtesy. Class is timeless, so I don't give a darn about what year it is...be a professional and at least say hi up front.
I don't know who lowered the bar so low that you guys seem to think its a burden to treat a fellow professional to a little courtesy, but grow the hell up and act like an adult instead of a whiny millennial with wings.

Introduce yourself to the FA(s) up front. Explain that you're a jumpseater from and say you'd like to check in with the front end crew. Go up front, wait if they're in the middle of something then usually something like "Good morning/afternoon/evening, I'm Pete Pilot from Air Greyhound, I was wondering if I could ride with you today to Bumscrubble, Hub?"

And go from there. It's fairly informal, 99% are very gracious, a handful want you to stroke their ego. Usually those ones don't commute. It's easy, you'll figure it out in no time flat.

You really should have at least 3 ID's in hand. Next time try to have your state issued Drivers License out as well, this way the crew really knows that you are serious about this stuff

We have a winner!

Not going to bother reading all the previous posts. You may have a seat in the cockpit via the gate agent-shes not the final authority-what if the seat/seats are MEL'd, there's low O2 available and a third person can't sit there >>you are there at the Captains whim and permission. Have a beef-dont do it there-get flight number and time and pass it to your ALPA/Union rep.
I ALWAYS go up, I ALWAYS ASK and let them know if a seat was assigned. Be a grown up-ASK.

My technique only:

- If I am jump seating I go up and introduce myself

- If I am non revving I go up and introduce myself

- If I am deadheading I go up and introduce myself

See a pattern here? :D What I'm getting at is, if I were the Captain I would greatly appreciate knowing who and where all available crew members are on board in the unlikely case we could use their help. It's happened plenty before.

Not to mention, putting a face to a name is always a pleasant way to do it. You meet some interesting folks that you may have only interacted with online. It's a win-win.

Jumpseat etiquette
 

From my experience it's the young kids and new to 121 ex mil guys that haven't been shown how to jumpseat. My old regional took time out of ground school to explain how to jumpseat but that's probably not very common. On my current commute there has been one relatively new former military guy showing up on Southwest and just taking a seat and not saying anything to anyone. I think he learned a lesson one day when the flight filled up and he had to go up front.

Funny is when, as it was explained to me, the passengers were deplaning and some douchebag captain jumped some guy in uniform's ass for not coming up and asking for a ride before the flight departed. The pilot just looked at him and said, "Really??? I'm a fractional pilot, and I'm on the fully-refundable fare ticket that paid your boat payment for this month, you dick."

Perfect.

Seriously? We had 8 DHers today...are you saying that all 8 of them should've come up and said hi?

You never know which Captain is gonna flip his **** if you don't ask permission. I personally had my ass handed to me by a crusty old AA captain for not checking in with him while on a positive space dh.