This is my favorite part, and the most overlooked. You need a ritual. Not a funeral (unless you want one), but a little action. I ate Barnaby’s favorite food—a greasy burger—on his grave. Yes, I looked insane. It made me laugh through the tears. You could donate his unopened food to a shelter, or plant a tree, or—here’s a weird one—write a fake Yelp review for your dog: "Five stars. Great snuggler. Would pet again."
The point is to actively remember them, not just passively miss them. Grief is sloppy. Make it creative. Make it yours. Your dog would want you to be a little weird about it. Trust me.