I go back and forth with this specific issue, since I do and don't allow dogs on the furniture. Primarily I only allow dogs that are invited onto the furniture, to lay on the furniture. If that doesn't make any sense I will explain.
With my own dog, she is allowed on all furniture in our home except for my parents bed, and our leather couches in the game room. That being said, she does NOT get on furniture when not invited to. She will not jump up on a bed or couch that isn't hers, until invited to come up. (i.e., she doesn't take the liberty to lay on furniture herself).
She sees laying on furniture with us as a reward for good behavior, a great run, or just because we want to snuggle with her. She will only stay on the furniture for so long, before she gets off to go lay on the cool hardwood floors.
The standards I uphold with my own dog, are applied to my guests dogs. If a guest dog takes the liberty to jump up on the furniture without being invited, they have to get off. Once they've decided to stay off, and go elsewhere, I will invite them to come on if they still want to.
I use couch and bed snuggle time as a reward that they look forward to. I tend to do this with a lot of other normal activities (i.e. treats, meal times, water, walks, cuddle time, fetch, etc.) These are normal every day routine and activties, but I make my dogs work for it, which also stimulates them mentally and physically. My dogs stay for at least 6 seconds before entering and exiting any door or gate, entering a car, entering/exiting a building, entering/exiting the dog park and sit and stay whilst other dogs approach us, kindly say hello, and go about our way. This is a standard I hold with all of my dogs, and for guests that are not used to this kind of training get special attention (solo walks, solo park time, solo feedings, etc) until they get the hang of it, and can do it along with the rest of the pack.
It also helps tremendously when they have someone other than you, that upholds the rules to follow. Binky, my resident dog, leads and shows all of our guests about how to act when staying with us. They often follow her around the house, if she goes to the living room and lies down, they will to. If she goes to get a drink of water, they will follow, if she goes upstairs to try to get away from them, they follow her lol. I honestly could not function as well if it wasn't for Binky. She's my biggest and best helper!!
The key is to be consistent! If you give in, or slip up one time, that's all ... (more)
I dog sit in their own home, so if they usually allow their pets on their bed then I do as well! One of the reason I love dog sitting so much is because I don't have my own dog with me at college, so I will take any chance I get to cuddle with a dog.
I just had a dog not only sleep in my bed at my home - they slept ON TOP of me. It was a sleepless night for me. The owner laughed and was like oh yes I forgot to tell you that. It went too far for me as I cannot be sleep deprived :)