Preheat your oven to 375°F. Line a baking sheet with parchment paper.
Cut the bread into ¾-inch cubes and place them in a large bowl.
Sprinkle the Italian seasoning, garlic powder, and 1/2 tsp salt over the bread. Toss to combine.
Drizzle the olive oil/melted butter (or both) over the bread cubes and toss again until they are all well-coated. Taste and add additional 1/4 tsp salt if needed.
Spread the bread cubes onto the baking sheet. Make sure they're in a single layer with a little space between each cube.
Bake for 10 to 20 minutes, or until the croutons are lightly golden brown. Fresh bread will take longer, but I recommend starting to check around the 10-minute mark.
Something to keep in mind is that the part of the crouton that is touching the baking sheet will be darker golden brown than the tops, so you might want to lift one up with some tongs to see how deep the color is.
Remove the croutons from your oven and allow them to cool completely. Store in an airtight container.