Take the mashed potatoes and spices to taste and blend them in a food processor with 1 tablespoon water, to soften them up. There are tons of optional ingredients you can add to this mix, based on what you already have laying around the kitchen. As I pointed out earlier, the point of these recipes is to make fancy-looking dishes from your leftovers, without having to add anything other than a few kitchen staples. Anyone who's made real traditional latkes knows to add a tablespoon of flour or matzo meal, chopped onions and an egg. Add them in if you've got them. If not, that's okay; either way they're still going to taste like fried potatoes.
Fire up a skillet over medium heat with cooking oil-whatever kind you use to fry things. While that's heating up, form the potato mix into latkes with your hands, each about the size of a cookie. It's easier to shape them on top of a sheet of aluminum foil, so they are easy to pick up and peel away when they're ready to go in the frying pan.
When the oil temperature is optimal, place each latke in the pan and fry it up. Cook one whole side, about 8 minutes, before flipping each over with a spatula to fry the other side. When they're golden brown on both sides, remove them from the skillet and pat the excess oil out with a paper towel. Then garnish them with green onions or chives if you have them.