Get involved with a training group of the breed/style of dog you want. Helping hands are always appreciated and you will have an inside track on litters that are not advertised I mass media. I started that with a new organization called NAVHDA back in the early 1980s and I never lacked for opportunities since.
You could do the same by helping out a trainer, they also have contacts that are outside of the channels everyone else uses. I have two that I am friends with and have gotten dogs from them when I wanted one.
The above are also sources one can use to find older pups and dogs as some owners cannot keep them for various reasons. With the current craziness and loss of jobs going on a pup or new dog could become a serious liability for them. A "rescue" in this manner would be advantageous to all involved.
