I use a recipe from Chef Rick Bayless:
1 medium red-skin potato
6 large eggs
1T yellow mustard
2T mayo
2T sweet pickle relish
Cut and boil the potato along with the the eggs in salted water.
Cool and peel eggs, scoop out yolks and set egg whites aside.
Mix yolks, potato and other ingredients with a fork.
I use a small ice cream scoop (i.e. the size of a melon ball) to school yolk mixture into the egg white shells, then I gently drag a fork across it.
You can garnish with whatever you want (I use paprika). Simple, but very tasty (I always get rave reviews on my deviled eggs).
He also has a jalapeño variation here:
https://parade.com/871608/solanahawkenson/rick-baylesss-creamy-jalapeno-deviled-eggs/