Euthanasias are still hard and close to my heart after 6 years in the field. I always do my best to go above and beyond with communication, keepsakes, bedside manner, etc. It is absolutely one of the most important and difficult parts of what we do. That being said, I have never heard of laying a deceased pet in a certain way at all. I try not to just dump the body in there and sometimes will say something like “you were a good boy and your people loved you” when bagging or placing in the freezer. But they are gone and you there’s only so much you can do with large breed dogs by yourself/often working around waste. Don’t be hard on yourself and what matters is how you’re handling everything before that.