I just completed my first LD journey.
I tipped my TE car attendant $10 on the first leg from FTW to CHI. A bit of a language barrier, but he was good.
On the LSL from CHI to ALB, I was in coach and went to get a can of Pepsi. This girl was very rude and I left nothing in her tip box, and it was apparent most everyone else felt the same, as there were only a few coins in it.
(Rude as in just muttering the price and turning her back to the register while holding her hand up above her shoulder for me to deposit money into while her back was still turned)
The LSL was 4+ hours late coming back from ALB to CHI and I was in no state to join a table at a dining car after running directly from the LSL to the TE that was waiting patiently for us.
The attendant brought my steak dinner and dessert to me in my room and I tipped him $10 right then and there because it meant that much to me. He continued to be most excellent and I handed him another $10 on the way out.
On the other hand, I shorted the breakfast attendant.
He looked up when I entered, I said "Good Morning" he literally barked "What?", and I repeated "Good Morning" and he grunted at me to inquire if I wanted breakfast...(No, I didn't want breakfast, I was just out looking to get barked at by a surly waiter).
I really wanted to turn around and leave, but it's not like being where you can just go elsewhere, and I did pay for it with my room.
So I said yes. Even my table-mates were taken aback by his attitude. I did leave a dollar because a friendly young woman did come refill our coffee just before he informed us that he was "gonna need this table".
And I gave $2 to the Chicago Metro lounge baggage hold attendant, because I was super grateful for that little perk that allowed me to walk all over town without my backpack.
I definitely took it on a case by case basis.
I did overhear the loud gentleman in the room across from me announce to the attendant that he was tipping up front "to get the good service", which I think was tacky, and the attendant seemed a bit offended as he assured him he will get good service regardless.