Adding the same ingredient twice, for two different roles. A few examples:
Tomato sauce: a single tomato, diced small, to add near the end, to improve the texture.
Curry: half of the onion gets grated and goes in the roux, with a bit of baking soda (so it melts down). The other half is diced larger, and gets added near the end as a plain veg. As a result I get a thicker and tastier curry.
Farofa: whatever filling I’m adding (pork rinds, bacon, banana, scrambled eggs…), I reserve some bits to add near the end as garnish. It’s both more pleasing to look and it allows people to pick a bit more of the filling if they so desire.
Breaded anything: seasoning goes both in the marinade and the flour / breadcrumbs.