"appropriate" means different things to different people. What I do depends on my order......If I order just coffee, I normally give a dollar tip. If I order food we give 2 dollars. When I order cokes (you pay..tip in bill) I still give a dollar. I am sure some give more and sure some give less....whatever you are comfortable with.
Thanks for the info. Rick. I have never used room service before but we have a balcony cabin this time and thought I might enjoy some coffee in the morning or evening on the balcony without getting dressed and going to get it. Didn't really know where to start as far as tipping. Your "appropriate" sounds reasonable to me.