Uni is my first dog and she slept in our bed since the first night. I kept a bell on her collar, and still do. While potty training, during the night if I heard the bell (meaning she was moving around) I would get up and take her to try and pee. This worked well for us.
Toto is my rescue boy and I got him when he was 8 yrs. He was already crate trained, so I didn't want to mess that up. He would sleep in the crate at night downstairs by himself, but as soon as the sun started coming up he would start to bark. Once it started getting cold, I took him upstairs to our room. I think he is used to the crate enough that when we go out, he is still fine in the crate, but of course prefers to sleep in bed with us.
Each dog is different. You just have to train a certain way that works for you and stick with it. I love that the dogs sleep in bed with us. Although, I don't love it when I wake up with a crooked neck or pinched nerve bc two little 5 pound dogs took over the Cal King bed and I was too "nice" to move them.
