There are two things we do with left over baked potatoes.
One is slice them thick and fry them in butter for breakfast mojo potatoes and the other is cut them in half the long way, scoop out the center, mash the center filling up with salt, dried onion, grated cheddar cheese and plain yogurt, fill the boats and bake in the oven.
I have also made potato salad before but it was not our favorite probably because I was too lazy to peel them.